Role of the Age Factor in Eye Regeneration in the Gastropod Achatina fulica

The dependence of the ability to regenerate the eye on the age of experimental animals was studied in the snail Achatina fulica. The degree of regeneration was estimated by light-microscopic and electrophysiological methods and by analyzing the motor response to visual stimuli. In older age groups, the number of regenerated eye-bearing tentacles decreased, whereas the period of regeneration increased. The regenerated eyes of the snails operated at the age of more than two months remained smaller than normal eyes even after six months. Regeneration of the distal part of the optic nerve was observed, and the regenerated eyes recovered the ability to respond to stimulation by light. In the electroretinogram, the responses of the regenerated eye, compared to the control, were characterized by lower amplitude and longer repolarization and refractory periods. Manifestations of the motor response to visual stimuli in the young snails with regenerating eyes could be regarded as evidence for the recovery of connection between the organ of sight and the central ganglia.     

Electroretinographic and ultrastructural study of the regenerated eye of the snail cryptomphallus aspersa

The electroretinographic responses of regenerated eyes of snails (C. aspersa) were studied by means of suction electrodes and single or repetitive flash stimulation. The eyes were fixed and observed under light and electron microscopy. The results indicate that the electroretinographic response of regenerated eyes does not differ from control eyes after dark adaptation. However, the repetitive stimulation of the regenerated eyes induced an earlier fatigue of the response, evident after the fifth stimulus. This fatigue is a function of light intensity. Ultrastructural features of the regenerated eyes are similar to those of the control eyes but regenerated eyes show smaller rhabdomeres, fewer photic vesicles, and fewer paracrystalline bodies. It is suggested that the regenerated eye lability to the repetitive stimulation might be due to the decrease in the amount of photic vesicles and paracrystalline bodies, to the decrease in membrane surface of the rhabdomeres, or to some other metabolic failure not distinguished at electron microscopic level, like the membrane ionic regulation. The appearance of photic vesicles in the axon cones of regenerated and stimulated cells also suggests a possible failure in the mechanism of transport of vesicles.     

Regeneration and molting effects on a proprioceptor organ in the dungeness crab,Cancer magister

Decapoda Crustacea molt in order to grow; some species, such as the Dungeness crab Cancer magister, achieve a very large size. Does sendory neuron hyperplasia in internal proprioceptors accompany this growth? To determine this, neurons in propodite-dactylopodite (PD) chordotonal organs were counted in first walking legs of juvenile (5th through 9th instar) and adult (10th through 13th instar) C. magister. We found that the PD organs of J5 crabs have about 56 neurons; the number increases to about 61 neurons in J6 crabs. Significant hyperplasia now occurs because an average of 79 neurons are found in the PD organs of J7 crabs. Little to no hyperplasia accompanies the several succeeding juvenile and adult molts (ca. 82–86 neurons are present). Because autotomized limbs are regenerated upon molting, we also examined how the number of PD organ neurons in regenerated legs compare with those of pristine legs. Newly regenerated legs (termed 1st stage regenerates) have fewer sensory neurons than do their contralateral pristine partners (65 vs 81); larger regenerated legs which have attained nearly normal size as a result of additional molts (2nd stage regenerates) still have fewer neurons than their pristine partners (69 vs 81). Additionally, in contrast to those of pristine walking legs, the elastic strand of PD organs from 1st stage regenerates is a misshapen sheet containing a cluster of small neurons with no obvious functional organization. Nonetheless, neurophysiological recordings indicate that all the receptor types typical for pristine legs (movement and position cells) are represented. The PD organs of 2nd stage regenerates differentiate to the shape and neuronal organization of pristine legs. © 1994 John Wiley & Sons, Inc.     

Multiple DNA contents in the haploid protonema of the mossFunaria hygrometrica sibth

Summary Cytofluorometry with fluorochrome Hoechst 33258 shows that caulonema cells in the protonema of the haploid mossFunaria hygrometrica endoreduplicate their DNA up to 8 or 16 C during normal development. The increase in DNA content depends on age and position of the cells in the filament and occurs in those cells, which normally do not undergo any further growth or division.Single cells from different positions between the tip and the tenth cell of the filament were isolated and regenerated to new protonema. Groth and differentiation of these regenerates depend on the age and position of the original cell. Cytofluorometry of the tip cells of these regenerates shows, that the higher DNA content is maintained during regeneration.     

A Focus on the Optical Properties of the Regenerated Newt Lens

Lens regeneration studies in the adult newt suggest that molecular aspects of lens regeneration are complete within 5 weeks of lentectomy. However, very little is known about the optical properties of the regenerated lens. In an aquatic environment, the lens accounts for almost all of the refractive power of the eye, and thus, a fully functional lens is critical. We compared the optical properties of 9- and 26-week regenerated lenses in the red spotted newt, Notophthalmus viridescens, with the original lenses removed from the same eyes. At 9 weeks, the regenerated lenses are smaller than the original lenses and are histologically immature, with a lower density of lens proteins. The 9 week lenses have greater light transmission, but significantly reduced focal length and refractive index than the original lenses. This suggests that following 9 weeks of regeneration, the lenses have not recovered the functionality of the original lens. By 26 weeks, the transmission of light in the more mature lens is reduced, but the optical parameters of the lens have recovered enough to allow functional vision.     

Insect-resistant plants with improved horticultural traits from interspecific potato hybrids grown in vitro

Summary Plants were regenerated from petiole calli of interspecific hybrids of Solanum tuberosum x S. berthaultii, an insect-resistant wild species. Callus culture was used to generate genetic changes to overcome the restricted recombination between the two genomes. Two plants out of 58 (3.5%) from calli of hybrid J114-1 showed stable and heritable differences from the hybrid over two cycles of evaluations in the field. Replicated trials were conducted in 1987 and 1988, using two populations of plants propagated by nodal cuttings from the original regenerates maintained in vitro. One regenerate showed insect resistance and increased marketable yield (approximately two fold) in the field. The other had higher levels of phenolic exudate in one of the two types of foliar trichomes associated with the insect resistance mechanism. Some desirable changes were discernible only in sexual progeny of regenerates, not in the regenerates themselves. In a backcross to S. tuberosum, 7 of 14 (50%) regenerates from hybrid F743-4 showed more progeny (up to 15-fold) with improved trichome traits and horticultural characteristics than the original hybrid. The variations were not associated with changes in ploidy. Fifteen plants obtained from these crosses are currently being incorporated into breeding lines. These results suggest that a period of callus culture followed by plant regeneration may aid in the introgression of desirable traits from wild species into crop plants.     

Evaluation of tentacle regeneration as a biological assay inHydra

Summary Tentacle number in non-buddingHydra attenuata, randomly selected from mass culture varies <0.5 tentacles over a 3 month period. Replicate samples of untreated regenerates (n=50–60), however, show some variability in mean tentacle number regenerated (S _x0.13–0.15). The variability is similar whether experiments are performed using randomly selected animals or animals with identical tentacle numbers. The variability is, further, not the result of profound differences in the time of tentacle initiation in individual animals.Addition of 10^–5 M glutamate or a methanol extract to the assay medium results in both an earlier appearance of tentacles and in more tentacles being regenerated during early time periods. The mean tentacle number of methanol extract-treated animals is significantly higher than the mean tentacle number of either control or glutamate-treated animals at all time periods examined.The distribution of tentacle number classes among regenerates is normal in control and glutamate-treated animals but nonparametric in methanol extract-treated animals, making statistical analysis of the data using Student'st-test in-appropriate. The usefulness of the Mann WhitneyU and Kruskal-Wallis tests is discussed, as is the appropriateness of tentacle regeneration as an assay forhydra morphogens.     

Effects of hypophysectomies and thyroxine replacement upon the initiation of tail regeneration in the lizard, Anolis carolinensis

A histological evaluation of the effects of hypophysectomy and throxine therapy in young tail regenerates was carried out in the small iguanid lizard, Anolis c. carolinensis. Hypophysectomy caused a delay but did not inhibit blastema formation. The growth of the ependyma into the wound region was delayed in hypophysioprivic regenerates by about a week. Growth and differentiation of hypophysioprivic regenerates after blastema formation was variable, ranging from virtually no growth to the formation of a differentiated but very small protuberance. However, actual tail elongation was inhibited by hypophysectomy. In those hypophysioprivic regenerates that did show signs of differentiation, muscle groups were poorly defined, scanty in appearance and not as well differentiated as the cartilage tube. Thyroxine treatment in the young hypophysioprivic regenerates stimulated normal growth and normal appearance and differentiation of promuscle and procartilage aggregates as well as the growth of the ependymal tube into the blastema.     

In vitro propagation and chromosome doubling of a Triticum crassum x Hordeum vulgare intergeneric hybrid

Summary In vitro culture of inflorescence tissue of a Triticum crassum (6x) x Hordeum vulgare cv. Bomi (2x) intergeneric hybrid resulted in the proliferation of totipotent callus from which plants were regenerated. Regeneration was also achieved from immature inflorescence callus of T. crassum but not from H. vulgare. T. crassum x H. vulgare regenerates had a somatic chromosome number of 28, identical to that of the original hybrid. Four chimeric plants with a partially doubled chromosome number were obtained by in vitro colchicine treatment of hybrid callus prior to induction of plant regeneration. All T. crassum regenerates had 35 chromosomes rather than the expected number of 42. Meiotic analysis of a 35-chromosome plant revealed an extremely abnormal meiosis which might be attributable to a complete disturbance in meiotic control system(s) including that of meiotic pairing.Dedicated to Professor Georg Melchers on the occasion of his 75th birthday.Contribution No. 624 Ottawa Research Station, Research Branch, Agriculture Canada, Ottawa, Ont. K1A OC6 (Canada)     

Interruption of proecdysis by autotomy of partially regenerated limbs in the land crab, Gecarcinus lateralis

In the land crab, Gecarcinus lateralis, autotomy of partially regenerated limbs before a critical stage in the premolt period results in (1) a very rapid decrease in the serum ecdysone titer, (2) a delay in the growth of partial regenerates remaining on the animal, (3) a delay in the deposition of gastroliths, and (4) a delay in cytological changes in the epidermis. Serum ecdysone titers remain low while new limb regenerates form at the sites of those removed. Ecdysone titers rise when these secondary regenerates complete basal regeneration. Premolt events, which had ceased at the time of autotomy of the partial regenerates, resume their normal patterns of development when ecdysone titers reach the level present in the serum at the time of this interruption. We propose that the effect of autotomy before a critical period is to reinitiate a normal proecdysis. The same pattern of events occurs following autotomy of partial regenerates of crabs without eyestalks, suggesting that the decrease of serum ecdysones is brought about by some mechanism other than changes in the titer of the molt inhibitory hormone.     

Regeneration of appendages in the large milkweed bug, Oncopeltus fasciatus

An analysis was made of the regeneration of legs and antennae of Oncopeltus. Amputations were performed on first instar larvae within 24 hr after hatching, and on later instars within 24 hr after ecdysis. The resulting regenerates were then measured at each instar. When amputations were performed soon after hatching, there was no significant effect on the duration of any instar. The regenerate was usually visible after the second post-operative ecdysis, and was smaller than a normal appendage (hypomorphic). Removal of the three distal segments of the antenna usually resulted in regeneration of only one segment which was abnormally long and showed a combination of the bristle patterns characteristic of the two most distal segments of the control. In a few such cases a partial intersegmental membrane was present in the regenerated segment. Removal of the tarsus resulted in a structurally complete regenerate which was smaller than the control tarsus. The largest leg regenerates were obtained when amputation was performed through the tibia. With amputation through the femur, a decrease in length of the remainder of this segment was observed after the first ecdysis. This type of amputation and amputation through the trochanter in some cases resulted in the formation of a globular stump containing tarsal claws. The results indicate that amputation of part of an appendage in Oncopeltus does not stimulate an increased growth rate in the stump, but merely causes reorganization of the stump material which subsequently grows at the normal rate. Since even the most hypomorphic regenerates contained well-formed claws, even though proximal parts were missing, it appears that the reorganization process must begin at the most distal point and proceed proximally.     

Exogenous orienting of attention depends upon the ability to execute eye movements

Shifts of attention can be made overtly by moving the eyes or covertly with attention being allocated to a region of space that does not correspond to the current direction of gaze. However, the precise relationship between eye movements and the covert orienting of attention remains controversial. The influential premotor theory proposes that the covert orienting of attention is produced by the programming of (unexecuted) eye movements and thus predicts a strong relationship between the ability to execute eye movements and the operation of spatial attention. Here, we demonstrate for the first time that impaired spatial attention is observed in an individual (AI) who is neurologically healthy but who cannot execute eye movements as a result of a congenital impairment in the elasticity of her eye muscles. This finding provides direct support for the role of the eye-movement system in the covert orienting of attention and suggests that whereas intact cortical structures may be necessary for normal attentional reflexes, they are not sufficient. The ability to move our eyes is essential for the development of normal patterns of spatial attention.     

The long-term effectiveness of different regimens of occlusion on recovery from early monocular deprivation in kittens.

Although the behavioural effects of an early period of monocular deprivation imposed on kittens can be very severe, resembling an extreme form of the human clinical condition deprivation amblyopia, they are not necessarily irreversible. Considerable behavioural as well as physiological recovery can occur if normal visual input is restored to the deprived eye sufficiently early, particularly if the other (initially non-deprived) eye is occluded at the same time (reverse occlusion). However, past work has shown that in many situations the improvement in the vision of the initially deprived eye that occurs during reverse occlusion is not retained following the subsequent introduction of binocular visual input. Furthermore, the vision of the other eye is often reduced as well, with the result that the eventual outcome is a condition of bilateral amblyopia. This study first examines the consequences of several periods of reverse occlusion whose onset and duration would be thought to maximize the opportunity for good and long-standing recovery of vision in the initially deprived eye. However, only in a very restricted set of exposure conditions did animals acquire good vision in one or both eyes; in most situations the final outcome was one of bilateral amblyopia. A second set of experiments examined the consequences of various regimens of part-time reverse occlusion, where the initially non-deprived eye was occluded for only part of each day to allow a period of binocular visual exposure, on kittens that had been monocularly deprived until 6, 8, 10 or 12 weeks of age. Whereas short or long daily periods of occlusion of the initially non-deprived eye resulted eventually in amblyopia in one, or usually both, eyes, certain intermediate occlusion times (3.5 or 5 h each day) resulted in recovery of normal acuities, contrast sensitivity and vernier acuity in both eyes, in animals that had been monocularly deprived until 6, 8 or 10 weeks of age, but not in animals deprived for longer periods. Experiments were done to establish some of the factors that contributed to the successful outcome associated with certain of the regimens of part-time reverse occlusion. It was established that recovery was just as good in animals in which the visual axes were vertically misaligned by means of prisms during the daily period of binocular visual exposure, thereby indicating that the visual input to the two eyes need not be concordant. However, animals that received equivalent visual exposure of the two eyes each day, but successively rather than simultaneously, all developed very severe bilateral amblyopia.(ABSTRACT TRUNCATED AT 400 WORDS)     

Haploid callus and regeneration of plants from anthers of Digitalis purpurea L.

Summary Production of callus from anthers of D. purpurea was obtained on several basal media supplemented with various amounts of auxins. Chromosome counts showed that the callus produced was haploid when the anthers 1) were of a dark-brown to black color, and 2) were cultured in the late tetrad stage of microspore development. Subsequent differentiation to plants at high frequencies was possible only 1) when the anthers had been cultured on the medium of Nitsch and Nitsch (Science 163, 85–87; 1969) supplemented with 5 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), 2) when the callus was transferred to the same medium but without 2,4-D, and 3) when it was cultured under continuous light from fluorescent lamps. Proliferation of the callus and regeneration of plants did not diminish through as many as 20 subcultures. The high frequency of regenerates permits the propagation of a distinct geno-type to a virtually unlimited number of plants. Diploid plants were obtained when the anthers had been cultured in the dark. Tetraploid plants were regenerated by callus from anthers which had been cultured in light. When the time of 2,4-D treatment was shortened a few haploid plants were produced which however did not survive transfer to soil. Cytological observations demonstrated that regeneration started from haploid callus, leading to intermediate degrees of ploidy and finally to diploid plants. Most of the regenerated plants were euploid and flowered and fruited normally under greenhouse and field conditions. If the anther-derived callus was cultured on the medium of Nitsch and Nitsch supplemented with 2.2 mg/l kinetin, plants regenerated only under photoperiodic conditions of 16 h light at 28° and 8 h dark at 20° but the survival was lowered to one third. These plants had a different leaf and flower morphology as compared to the control without kinetin and to the starting material, but their progeny was again essentially normal.     

The effect of retinoic acid on positional memory in the dorsoventral axis of regenerating axolotl limbs

We investigated the effect of retinoic acid (RA) on pattern regulation in the dorsoventral (DV) axis of regenerating axolotl limbs. Half and double half dorsal and ventral zeugopodia (lower arms or legs) were amputated through their distal ends, and 4 days later the animals were injected intraperitoneally with 50 (large animals) or 100 (small animals) micrograms RA/g body wt. Half and double half dorsal and ventral zeugopodia of uninjected axolotls, and sham-operated zeugopodia of untreated and RA-treated limbs served as controls. Skeletal patterns and the DV muscle patterns of control and experimental regenerates were then analyzed. Sham-operated zeugopodia of uninjected animals regenerated normally. Sham-operated, RA-treated zeugopodia regenerated normally with proximodistal duplications. Sixty percent of uninjected control dorsal half zeugopodia, 80% of control ventral half zeugopodia, and 100% of control double dorsal and double ventral zeugopodia regenerated distally, but the regenerates did not reconstitute the muscle pattern of the missing half. Thirty-eight percent of RA-treated ventral half zeugopodia and 78% of RA-treated double ventral zeugopodia failed to regenerate distally. Of those cases that did regenerate distally, none regenerated the muscle pattern of the missing half. By contrast, 100% of RA-treated dorsal half zeugopodia regenerated distally and all completed the normal DV muscle pattern. Forty-one percent of RA-treated double dorsal zeugopodia failed to regenerate, but of the remainder that did regenerate, 50% completed the normal DV muscle pattern. These represented eight cases, six of which regenerated single limbs, and two of which regenerated twin limbs, each with a normal DV muscle pattern. We interpret these data to mean that RA ventralizes the positional memory of blastema cells in the DV axis.     

The effects of Acanthaster planci predation on populations of two species of massive coral

Species of the freshwater planarian genus Polycelis have a variable number of eyes in the head, typically more than a hundred. To elucidate the mechanisms determining the number of eyes, we investigated the relation between eye number and body length in Polycelis sapporo (Ijima & Kaburaki), a non-fissioning species, and P. auriculata Ijima & Kaburaki, a fissioning species. In P. sapporo reared at 7–8 °C, a positive correlation existed between number of eyes and body length. Eye number decreased with starvation. A similar correlation was true of P. auriculata. In specimens of P. auriculata undergoing regeneration, the rate of eye formation was higher in newly formed heads originating from larger tail-pieces than in those from smaller pieces. As a head regenerated from a tail piece or as the body size increased with feeding, the number of eyes increased. These results suggest that the number of eyes in an individual of Polycelis is determined by body length. The fine structure of the photoreceptor and pigment cells in the eyes of P. auriculata is similar to that of comparable cells in the pair of eyes in Dugesia despite the difference in the number of cells comprising an eye.     

Analytical study of Xenopus hindlimb regenerate with special reference to muscle regeneration

Amputated hindlimbs of Xenopus laevis, develop various types of regenerates in relation with amputation level as well as stage development. The present experiments is an attempt to study the histological characteristics of Xenopus regenerations, i.e., rational changes of tissue components along the length of the regenerated part with special emphasis on the degree of muscle regeneration. Four types of regenerates were studied viz; a 4th toe obtained from a completely restored regenerated limb at 126 days after amputation of limb at base level in stage 51. An amputated limb with no external sign of regeneration of limb at thigh level in stage 60. A spike-shaped regenerate at 96 days after amputation of limb at shank level in stage 63. A spike-shaped regenerate at about 2 years after amputation of limb at shank level in stage 60. Cross sectional areas of muscle, skin gland, epidermis and cartilage in each of the four types of regenerates were measured with Image Analyzing Apparatus (VIP 121 CH, Olympus Co.). The relative area of each tissue was expressed as a percentage of the cross sectional area of the limb. The obtained values were plotted along the length of the regenerate. Digitiform regenerates were found to be more or less similar to the control limbs, i.e., provided joints and muscle, while the heteromorphic spike or rod shaped regenerates were simply provided with cartilaginous axial core without joint formation. Muscle area were reduced rapidly near the amputation area of these heteromorphic regenerates with no more continuation in the regenerated tissue. It is interesting to mention that percentage cartilage area of about 2 years old spike regenerate was higher than that of similar 96 days regenerate. In addition muscle regeneration was completely absent even in such an aged regenerate. The area showed fairly similar ratio irrespective of the external appearance of the regenerate. In 32 regenerates of which limbs were amputated at various developmental stages ranging between stage 51 and adult stage, the histological condition of muscle at the amputation site, were well observed. In all digitated types of regenerates even in those with reduced number of toes, muscles were found grown well in the regenerates. In heteromorphic regenerates without toe formation muscle did not usually regenerate. In few cases, however, a small mass of myoblastic like cells or small aggregation of differentiated muscle cells without any structural continuation with the stump muscles, were seen to develop in the midst of the regenerate.(ABSTRACT TRUNCATED AT 400 WORDS)     

Measurement of Myopia and Normal Human Choroidal Thickness Using Spectral Domain Optical Coherence Tomography

Myopia is a common ophthalmic deficiency. The structure and function of choroid layer is assumed to be associated with myopia. In this study, a laboratory developed spectral domain optical coherence tomography scanning system is used to image human eyes. The axial resolution of the system is about 7 μm, and the acquisition rate is 100 kHz. Firstly, a cross-sectional image was acquired by averaging 100 images from imaging posterior segment of each eye. The choroid thickness was measured by 11 discrete points. The average thickness of normal human eyes was (0.296 ± 0.126) mm, whereas the average choroid thickness of myopic eyes was (0.220 ± 0.095) mm. Afterwards, the T test is used to calculate the data statistically. The analysis of the final result is based on the average thickness measured and the thickness of each measuring point. There was a significant difference in choroid thickness between myopia and normal eyes (P value < 0.01), which indicates that the choroid thickness of myopia was significantly thinner than that of normal eyes. Besides, there are findings that the choroidal thickness in nasal side is thinner than that in the fovea and temporal side in each eye. The choroidal thickness on temporal side in myopia eye has the most significant difference comparing with that in normal eye. The comprehensive evaluation of myopia and normal choroidal thickness using spectral domain optical coherence tomography may provide an important reference for the development of medical methods for diagnosis and treatment of myopia.     

Eye morphology and visual acuity in the pipevine swallowtail (Battus philenor) studied with a new method of measuring interommatidial angles

Because of the important role sensory systems play in the behaviour of animals, information on sensory capabilities is of great value to behavioural ecologists in the development of hypotheses to explain behaviour. In compound eyes, interommatidial angles are a key determinant of visual acuity but methods for measuring these angles are often demanding and limited to live animals with a pseudopupil. Here we present a new technique for measuring interommatidial angles that is less demanding in terms of technology than other techniques but still accurate. It allows measurements in eyes without a pseudopupil such as dark eyes or even museum specimens. We call this technique the radius of curvature estimation (RCE) method. We describe RCE and validate the method by comparing results from RCE with those from pseudopupil analysis for the butterfly Asterocampa leilia. As an application of RCE we measure the eyes of the butterfly Battus philenor, a species whose visually guided behaviour is well known but whose eye structure and visual acuity are unknown. We discuss the results of the eye morphology in B. philenor in relation to their behaviour and ecology. We contend that RCE fills a gap in the repertoire of techniques available to study peripheral determinants of spatial resolution in compound eyes, because it can be applied on species with dark eyes. RCE then opens up for sampling a larger number of specimens, which, in combination with being able to use museum specimens, makes it possible to quantitatively test ecologically and evolutionarily driven hypotheses about vision in animals in a new way.     

Phylogeny of the Myriapoda – Crustacea – Insecta: a new attempt using photoreceptor structure*

According to molecular sequence data Crustacea and not Myriapoda seem to be the sister‐group to Insecta. This makes it necessary to reconsider how the morphology of their eyes fit with these new cladograms. Homology of facetted eye structures in Insecta (Hexapoda in the sense of Ento‐ and Ectognatha) and Crustacea is clearly supported by identical numbers of cells in an ommatidium (two corneageneous or primary pigment cells, four Semper cells which build the crystalline cone and primarily eight retinula cells). These cell numbers are retained even when great functional modification occurs, especially in the region of the dioptric apparatus. There are two different possibilities to explain differences in eye structure in Myriapoda depending on their phylogenetic position in the cladogram of Mandibulata. In the traditional Tracheata cladogram, eyes of Myriapoda must be secondarily modified. This modification can be explained using the different evolutionary pathways of insect facetted eyes to insect larval eyes (stemmata) as an analogous model system. Comparative morphology of larval insect eyes from all holometabolan orders shows that there are several evolutionary pathways which have led to different types of stemmata and that the process always involved the breaking up the compound eye into individual larval ommatidia. Further evolution led on many occasions to so‐called fusion‐stemmata that occur convergently in each holometabolic order and reveals, in part, great structural similarities to the lateral ocelli of myriapods. As myriapodan eyes cannot be regarded as typical mandibulate ommatidia, their structure can be explained as a modified complex eye evolved in a comparable way to the development to the fusion‐stemmata of insect larvae. The facetted eyes of Scutigera (Myriapoda, Chilopoda) must be considered as secondarily reorganized lateral myriapodan stemmata, the so‐called ‘pseudo‐compound eyes’. New is a crystalline cone‐like vitreous body within the dioptric apparatus. In the new cladogram with Crustacea and Insecta as sister‐groups however, the facetted eyes of Scutigera can be interpreted as an old precursor of the Crustacea – Insecta facetted eye with modified ommatidia having a four‐part crystalline cone, etc. as a synapomorphy. Lateral ocelli of all the other Myriapoda are then modified like insect stemmata. The precursor is then the Scutigera‐Ommatidium. In addition further interpretations of evolutionary pathways of myriapodan morphological characters are discussed.