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1.
Although holotype material of Calamophyton primaevum Kläusel and Weyland has not been available since the Second World War, two fertile specimens of that species are in the personal collection of Professor H. Weyland. The purpose of this paper is to disclose the complexity of the organization of the fertile appendage. Formerly it was believed to consist of one segment that had dichotomized once and that had borne two pendulous sporangia, one at each branch. Numerous degagements of sporangia have revealed a complex morphology, consisting of one main segment divided into two secondary segments. Each supports three recurved side stalks which in turn bear 2 sporangia, a total of 12 sporangia. Each secondary segment terminates in two elongated projections. The morphology of the fertile organs is compared with that of two other species, C. bicephalum Leclercq and Andrews and C. forbesii Schopf. Great similarity of organization exists between C. primaevum and C. bicephalum. The possible synonymy of these two species is discussed.  相似文献   

2.
SYNOPSIS. Haemogregarina boueti França, 1910, was found to be the commonest blood parasite in the common toad, Bufo regularis Reuss, in Egypt. The rate of infection was about 30% (of 689 toads examined). In properly fixed blood films, the parasites were almost exclusively intraerythrocytic. Most characteristic was the encapsulated “elongate” form averaging 22.3 by 6 μ with a more-or-less central nucleus and a pointed, slightly bent, posterior end. Infected red cells were conspicuously hypertrophied and their nuclei were markedly displaced and frequently broken into 2-4 parts. Young and growing blood forms as well as two types of hepatic schizonts are described for the first time. Schizonts of the first type develop in hepatic cells, are 28–30 μ in diameter and produce numerous elongate oval merozoites about 8 × 2.2 μ radially arranged around a residual body about 10 μ in diameter. Schizonts of the second type start their growth in erythrocytes but later complete their development as free bodies in the liver sinusoids. When mature, they are 32–35 μ in diameter and produce a larger number of thin merozoites about 8 × 1.5 μ, surrounding a larger residual body about 19 μ in diameter.  相似文献   

3.
Sunanda Pal  N. Pal 《Grana》2013,52(2):141-148
The examination of spores belonging to eight species representing five genera of Polypodiaceae reveals that they are typically free, anisopolar and monolete (bilateral). In a majority of cases the spores are yellow and have a short laesura—about half the length of the greater equatorial axis of the spore. Generally, the spores are elliptical in polar view and plano-convex to concavo-convex in profile view but in cross section they vary in shape. The average measurements in equatorial plane range from 44 μ to 71 μ whereas in the polar direction they vary from 27 μ to 47 μ. The exine is thin (about 2.5 μ and nearly smooth (laevigose-scabrous-foveolose) in Microsorium and Phymatodes but in the other investigated genera, it is thicker, possessing different types of projections. P: E varies from 4.6 to 5.5: 8. Oil globules are present in the spores of some species.

Available data on morphology of spores of Polypodiaceae have been tabulated in two tables on a comparative basis and their importance in taxonomy and phylogeny of some genera have been discussed.  相似文献   

4.
The name Crenaticaulis verruculosus is proposed for slender, pseudomonopodially and dichoto-mously branching plants that bore opposite to subopposite sporangia along the stem and two rows of prominent, multicellular teeth on opposite sides of the terete axis. Epidermal cells were either narrow and elongate parallel to the stem or short with a papillate outer tangential wall. Axillary tubercles were present on one side of the stem near lateral branches. Some tubercles bore remnants of branches. Sporangia dehisced along their distal margins into two unequal halves. No spores were found. Occasional short lengths of stem were petrified by iron pyrite. Sections revealed a cortex consisting of four to six rows of thick-walled cells and a xylem strand. The strand was elliptical in transverse section and maturation was exarch. Tracheids were chiefly scalariform. It is suggested that the so-called axillary tubercles, known in several plants of Devonian age, were scars of rhizophores like those in the modern genus Selaginella. The plant is referred to the subdivision Zosterophyllophytina.  相似文献   

5.
A new genus from a Middle Devonian locality near Cairo, N. Y., is described. Actinoxylon gen. nov. is based upon pyritic petrifactions. Three orders of branching are present: penultimate branch, ultimate branch, and leaf. The penultimate branch bears spirally arranged ultimate branches and leaves, the leaves apparently replacing the branches in the spiral. The ultimate branches bear opposite to subopposite and decussate leaves. The leaves are non-planated, unwebbed structures which show at least three dichotomies. Each segment of the leaf is terete as are all other axes. Internally the penultimate branch has a six-lobed actinostele with mesarch protoxylem areas, one or two per lobe. Secondary xylem is visible in the oldest parts of several specimens. The xylem has helical-reticulate, reticulate, scalariform and circular-pitted elements. The presumptive areas of phloem are occupied by cells with dark contents. The cortex is composed of a parenchymatous inner region and a sclerenchymatous outer region. The ultimate branch traces are at first three-lobed protosteles, later becoming four-lobed. Several ultimate branch traces also possess secondary xylem while within the cortex of the penultimate branch. The leaf traces are terete strands. Below each forking of a leaf segment there is a corresponding forking of the vascular strand. Actinoxylon is compared with the progymnosperms Actinopodium, Svalbardia, Archaeopteris, Siderella, and Tetraxylopteris. The anatomy of the penultimate branch of Actinoxylon is similar to that of Actinopodium, Archaeopteris macilenta, and Siderella. The ultimate branch traces of Archaeopteris and Actinoxylon are similar. The ultimate branch stele and pattern of trace formation in Actinoxylon is similar to the stelar configuration and trace formation in the r + 2 axes of Tetraxylopteris schmidtii. The unwebbed leaves are similar to those of Archaeopteris fissilis, Svalbardia, and the terminal units of the Aneurophytales.  相似文献   

6.
SYNOPSIS. Lankesteria barretti n. sp. (Eugregarinida, Diplocystidae) is named from the mosquito Aedes triseriatus in Texas. The young cephalins occur within the midgut epithelial cells. When they reach a length of about 150–200 μ they rupture the host cell and are released into the space between the epithelium and the peritrophic membrane, becoming gamonts. These grow to about 140–310 by 40 μ at the anterior end and 12 μ at the posterior end. When the host pupates they enter the lumen of the Malpighian tubules; pairs join in syzygy by their anterior ends and later more laterally. Each pair forms a spherical gametocyst about 60–100 μ (exceptionally 250 μ) in diameter. A large number of oocysts develop in each gametocyst. The mature oocysts are spindle-shaped, 11 by 5.4–5.7 μ, and contain 8 elongate sporozoites and a refractile residuum. The gametocyst wall breaks down, releasing oocysts in the Malpighian tubules of the host when it is adult. The oocysts pass out in the feces and presumably infect new larvae by ingestion. The cephalins and gamonts of L. barretti differ from those of L. culicis (of Aedes aegypti) in having a relatively anterior instead of a central nucleus and in lacking a noticeable mucron; its longitudinal folds are not as well-developed as in L. culicis, and its paraglycogen granules are larger. The fine structure of L. culicis and L. barretti is described in detail. Their gamonts have a polar ring but no definite conoid. The taxonomy of the genus is reviewed, but its species have been so poorly described that it is impossible to be sure whether they are all really Lankesteria. About 19 species have been described (5 from turbellaria, 8 from tunicates, perhaps 1 from Amphioxus, 1 from the chaetognath Sagitta sp., 1 from Phlebotomus and 3 from mosquitoes).  相似文献   

7.
SYNOPSIS. A new species of coccidium, Eimeria macusaniensis n. sp., is described from the alpaca Lama pacos in Macusani, Peru. The oocysts are ovoid to piriform, 81–107 by 61–80 μ (mean 93.6 by 67.4 μ) with a micropylar cap and elongate ovoid sporocysts 33–40 by 16–20 μ (mean 36.3 by 18.3 μ).  相似文献   

8.
The gross anatomy of the arteria cerebri media inCercopithecus aethiops andPapio anubis was studied and compared statistically. Several features appeared to be species characteristic. InCercopithecus aethiops the first branch, r. striati, arose directly from the main artery, however, inPapio anubis, r. striati arose from r. orbitales the second major branch. InCercopithecus aethiops, r. orbitales and r. frontales arose by a common trunk from the a. cerebri media and inPapio anubis these two branches had separate origins. In both species r. temporales arose from two trunks, on either side of the a. sulcus centralis. Each trunk of r. temporales divided into two or three branches inCercopithecus aethiops and three or four branches inPapio anubis. The last portion of the a. cerebri media, r. parietales, divided into two trunks inCercopithecus aethiops and continued as a single trunk inPapio anubis. In the former, r. parietales sent one or two branches to the sulcus intraparietalis and sulcus lunatus while sending one branch to the gyrus postcentralis. In the latter, r. parietales sent two or three branches to the sulcus intraparietalis, three or four to the sulcus lunatus and one to the gyrus postcentralis.  相似文献   

9.
The stem, rachides, and pinnae of Archaeopteris macilenta, formerly considered to be a fern of Devonian age, comprise a branch system in which the ultimate divisions heretofore referred to as pinnules are the leaves. The primary vascular system of the “frond” is a lobed siphonostele from which leaf traces arise in a spiral sequence. The anatomy of the “rachis” and of the “pinnae” is shown to be similar to that of the stem, Callixylon, which bore these “fronds.” Branching, epidermal pattern and stomates are described for the spirally arranged leaves (fertile pinnules). Attachment and dehiscence of sporangia as well as their stomates are reported. Archaeopteris is retained in the Class Progymnospermopsida which includes plants with gymnospermous anatomy and pteridophytic reproduction. It is suggested that Actinopodium, Svalbardia and Siderella are related closely to Archaeopteris and that this group of genera shows evolutionary stages in webbing of leaves and planation of branch systems. The opportunities for ontogenetic studies of the arborescent genus Archaeopteris are pointed out.  相似文献   

10.
Ortholinea alata n. sp. is described from the northern butterfly fish, Chaetodon rainfordi collected at Heron Island, Great Barrier Reef, Australia. Spherical, disporous trophozoites (10–15 μ) and spores were observed in the lumina of kidney tubules and collecting ducts. Spores are broadly triangular with two short, broad processes that extend dorsoventrad from the posterior end of each of the two spore valves. Valves are bisected by a suture in the plane of the polar capsules. Spores are 12.6 μ (length) × 9.6 μ (width) × 9.9 μ (length), and at the anterior end contain two spherical, divergent polar capsules measuring 4.6 ( 4.1 –5.1) μ. Sporogenesis is similar to that of renal Sphaerospora spp.: the intraluminal trophozoites of O. alata n. sp. correspond to pseudoplasmodia described for Sphaerospora spp. and no large, multinucleate plasmodia are formed. No significant histopathological changes were observed in the kidneys of infected fish.  相似文献   

11.
The morphology of Nosema whitei is described from 4 host beetles, Tribolium castaneum, T. confusum, T. anaphe, and Oryzaephilus surinamensis. The effect of host species on the sizes of the various stages was small. The predominant schizogonic stages were mononuclear (26%) and binuclear (73%) although schizonts with up to 5 nuclei were seen. In stained preparations the schizonts were approximately 2.7–7.0 μ in diameter. The sporonts, which do not divide, were elongate (5.6 × 3.1 μ), and had 1 or 2 nuclei. Both the sporoblast (4.2 × 2.2 μ) and the spores (3.5 × 2.0 μ) were binucleate. Fresh spores averaged 4.6 × 2.9 μ. The polar filament length ranged from 75 to 135 μ (mean = 112 μ). The only tissue found infected was the fat body. Host species, dose, and temperature were all found to affect the generation time, which ranged from 8 to 17 days.  相似文献   

12.
SYNOPSIS. Three new species of coccidia are described from the alpaca Lama pacos from Peru. These are the first species of coccidia to be named from this host. The oocysts of Eimeria lamae n. sp. are ellipsoidal, occasionally ovoid, 30–40 by 21–30 μ (mean 35.6 by 24.5 μ) with elongate ovoid sporocysts 13–16 by 8–10 μ (mean 15.3 by 8.5 μ). The oocysts of Eimeria alpacae n. sp. are ellipsoidal, rarely ovoid, 22–26 by 18–21 μ (mean 24.1 by 19.6 μ), with ovoid sporocysts 10–13 by 7–8 μ (mean 11.0 by 6.8 μ). The oocysts of Eimeria punoensis n. sp. are ellipsoidal, occasionally ovoid, 17–22 by 14–18 μ (mean 19.9 by 16.4 μ), with ovoid sporocysts 8–11 by 5–7 μ (mean 9.2 by 6.1 μ).  相似文献   

13.
Individual leaves of perennial ryegrass cv. Aberystwyth S23 of two leaf ages and at two levels of nitrogen fertilisation were point inoculated with Puccinia coronata f.sp. coronata in a growth chamber. In general, there was no significant difference in the lifespan of inoculated versus control leaves. However, the higher rate of nitrogen extended leaf lifespan more markedly in rusted than in control leaves. Uredospore production varied according to leaf age: colonies on juvenile leaves produced three times as many spores as those on mature leaves.  相似文献   

14.
The pinnately compound leaves of Swietenia spp. have numeroussmall nectaries on petiole, rachis, petiolules, and both surfacesof all leaflets. Nectaries are circular to elongate, eitherlevel with the epidermis or slightly raised or depressed. Thesecretory surface is usually smooth even under high SEM magnification.Each nectary has an outer zone of three or four cell layersof slightly elongate and densely cytoplasmic cells subtendedby two layers of rounded cells with thickened walls and lightlystaining cytoplasm. Proximity of nectaries to vasculature isvariable and seems to be only fortuitous. Meliaceae, Swietenia, mahogany, nectary anatomy, extrafloral nectaries, foliar nectaries  相似文献   

15.
Tucker, Shirley C. (Northwestern U., Evanston, III.) Development and phyllotaxis of the vegetative axillary bud of Michelia fuscata . Amer. Jour. Bot. 50(7): 661–668. Illus. 1963.—The vegetative axillary buds of Michelia fuscala are dorsiventrally symmetrical with 2 ranks of alternately produced leaves. The direction of the ontogenetic spiral in each of these buds is related both to the symmetry of the supporting branch and to the position of the bud along the branch. On a radially symmetrical branch, all the axillary buds are alike—all clockwise, for example. But in a dorsiventrally organized branch the symmetry alternates from clockwise in 1 axillary bud to counterclockwise in the next bud along the axis. Leaf initiation and ontogeny of the axillary apical meristem conform with those of the terminal vegetative bud. The axillary bud arises as a shell zone in the second leaf axil from the terminal meristem. During this process the axillary apex develops a zonate appearance. The acropetally developing procambial supply of the axillary bud consists wholly of leaf traces. At the nodal level the bud traces diverge from the same gap as the median bundle trace of the subtending leaf. Only the basal 1–2 axillary buds which form immediately after the flowers elongate each year, while the majority remains dormant with 3 leaves or fewer.  相似文献   

16.
SYNOPSIS Eimeria angusta Allen, 1934 and E. bonasae Allen, 1934 are redescribed from a ruffed grouse Bonasa umbellus. Oocysts of E. angusta were ellipsoidal to elongate ovoid, had micropyles and were 28-37 by 15-19 μ (mean 32.5 by 17.1 μ), with a length-width ratio of 1.67-2.19 (mean 1.91). Eimeria bonasae oocysts were spherical to subspherical and 18-25 by 18-23 μ (mean 21.6 by 20.6), with a length-width ratio of 1.00-1.16 (mean 1.05).  相似文献   

17.
The pollen organ Feraxotheca gen. n. is described from Pennsylvanian age coal balls from the Lewis Creek, Kentucky, locality. The fructifications consist of bilaterally symmetrical synangia composed of a basal pad supporting elongate sporangia that are laterally appressed for the entire length of the sporangial cavities. Sporangial tips extend over the center of the synangium and delimit a small open area, while the bases arise from a parenchymatous cushion that is bounded by short tracheid-like cells. Each synangium is borne on the surface of an expanded pinna tip and is surrounded by a small amount of laminar tissue that envelopes the base of the synangium. Ultimate pinnae are rectangular in transverse section, possess an elliptical vascular bundle surrounded by canals containing a yellow froth-like substance, and have a cortex of elongate cells that radiate from the center of the axis. Sporangia contain small (40–64 μm), radial, trilete spores ornamented by regularly spaced coni or blunt tipped grana. Feraxotheca is compared with the compression genus Crossotheca and some new ideas are advanced concerning the morphology of this compression genus. The obvious differences between Feraxotheca and other lyginopterid pollen organs strongly suggests that the Lyginopteridaceae, as it is currently interpreted, is an unnatural family.  相似文献   

18.
Six species of Cabomba have been examined although the anatomy of the vegetative axes is based on the study of only C. caroliniana and C. palaeformis. A plant consists of an erect short shoot with decussate leaves which bears axillary flowering shoots and rhizomes. A rhizome bears decussate leaves and may also form axillary flowering shoots or turn upward and become a new short shoot. The phyllotaxies of the flowering shoots are proximately decussate or ternate (C. piauhyensis). The flowering shoots with decussate phyllotaxy change to 1/3 phyllotaxy distally; they bear axillary flowers proximally, and extra-axillary flowers distally. Flowering shoots with ternate phyllotaxy do not change distally but each produces first axillary and then extra-axillary flowers. Decussate vegetative axes and flowering shoots have four vascular bundles; ternate vegetative axes and flowering shoots have six vascular bundles, distantly paired into two or three vascular bundle-pairs, respectively. An elliptical vascular plexus occurs at each node. Each leaf receives one bundle-pair from one trace and each flower three bundle-pairs. A two-level receptacular vascular plexus occurs in flowers; the proximal, larger portion provides traces to perianth and stamens and the distal, smaller portion becomes carpellary traces. Each of the three sepals typically receives five branch traces from a basal principal trace, and each of the three petals receives, typically, three branch traces from a basal principal trace. Sepals and petals generally occur in a single, basally connate whorl. Each stamen receives one trace. Each stamen of three-stamen flowers is opposite a petal; each stamen of six-stamen flowers is aligned with an interval between a petal and adjacent sepal. Each staminal trace, which is just above the principal petal trace, in a three-petal flower, is frequently adnate to the latter trace. Each carpel receives one principal trace from the distal, small extension of the receptacular plexus, and each principal trace becomes three conventional veins of a carpel. Ovules may be borne directly over one of the veins or in any position between veins and are supplied by branches of the nearest vein or nearest two veins. All traces, ovular supply veins and the proximal portions of all veins are amphicribral. The several anatomical and morphological differences in vegetative axes and flowers between Cabomba and Brasenia suggest a greater taxonomic distance between the two genera than commonly supposed. It is suggested that extra-axillary flowers in 1/3 helical and ternate flowering shoots of Cabomba might be advantageous in preventing anthesis of flowers beneath peltate leaves. The aberrant position might be the initial evolutionary step toward what, in other nymphaeaceous genera, has shifted each flower to an adjacent helix. It is proposed that the zigzag stem accompanying the trigonal and sympodial flowering shoots may offer greater stability and floatability in water than the monopodial form. Several suggestions are offered for the variability of ovular positions: 1) the variability is a vestige of former laminar placentation in conduplicate carpels; 2) it is a vestige of a primitive condition antedating the current close association of ovules with ventral carpellary veins; 3) it is an early stage of evolution which might have terminated in laminar placentation and cantharophily, but which was replaced by a trend toward myophily.  相似文献   

19.
SYNOPSIS. Eimeria bateri Bhatia, Pandey, Pande, 1965 is described from the Hungarian quail Coturnix c. coturnix for the first time in the U.S. Its oocysts are either ellipsoidal or ovoid, 14–28 by 12–19 μ with a mean of 20.5 by 15.3 μ. Its sporocysts are elongate ovoid, with a Stieda body, 8–12 by 6–9 μ with a mean of 10.3 by 7.5 μ. Two coccidia-free chicks 8 days old were inoculated with 50,000 oocysts each of E. bateri, but patent infections did not occur. This coccidium is therefore presumably host-specific.  相似文献   

20.
ABSTRACT. New information on the life cycle and fine structure of Pilosporella chapmani, a microsporidium of the mosquito Aedes triseriatus, is presented. Pilosporella chapmani is shown to have two sporulation sequences, one of them being involved in transovarial transmission. One sequence, involving meiosis and production of a moniliform sporogonial plasmodium, occurs in the larval fat body, resulting in eight uninucleate, spherical, and fully developed spores. The other occurs in oenocytes of adult mosquitoes and results in isolated, binucleate, elongate, and thin-walled spores. Also, for the first time, metabolic products are shown to be expelled into the surrounding host tissues through the wall of the sporocyst.  相似文献   

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