Comparative Anatomical Studies on the Vessel Elements of Eight Genera in Magnoliaceae

This paper deals mainly with comparative studies on vessel elements of secondary xylem in Chinese Manglietia, Manglietiastrum, Alcimandra, Parakmeria, Paramichelia, Tsoongiodendron, Aromadendron and Liriodendron. There are some differences between the genera in vessel element length and width. Manglietia species all have scalariform perforation plates, only a few also have simple perforations. The other genera have scalariform perforation plates. only one (Tsoongiodendron odorum Chun) has simple perforations in addition. There are no spiral thickenings in Manglietia except for one species [Manglietia chingii Dandy (M. temuipes Dandy)] . Paramichelia and Liriodendron have no spiral thichenings, but they are present in the other genera. In addition, some other differences in vessel elements between these 8 genera are also discussed.     

八属木兰科植物木材导管分子的比较解剖

本文比较描述了我国木兰科木莲属、华盖木属,长蕊木兰属,拟单性木兰属,合果木属,观光木属,香木兰属和鹅掌楸属等8属22种植物次生质部的导管分子,这些导管分子的长度和宽度都有差异,木莲属的所有种中都有具梯状穿孔板的导管分子,但在少数种中偶然可见到单穿孔,在其它属中,也都有具梯状穿孔板的导管分子,仅在观光木属中偶见的单穿孔,木莲属大多数种均无螺纹加厚,仅桂南木莲一种除外,另外,除了合果木属和鹅掌楸无螺纹加厚外,其余均有此种加厚,各属的导管分子还存在其它一些差异。     

Morphology and taxonomy of Chondria tenuissima and Chondria dasyphylla (Rhodomelaceae,Rhodophyta) from European waters

Recent collections of fertile Chondria tenuissima, the type species of the genus, and Chondria dasyphylla (Woodward) C. Ag. from European waters have clarified details of their morphology and reproduction. This has allowed more detailed comparisons with southern Australian material hitherto placed under these species and has shown that neither occurs on these coasts. Records of these species from other countries may thus be open to doubt.

Ruthenium Red-positive cell wall thickenings are present in some populations of both species. In C. tenuissima the thickenings are thin and lenticular or band-like, occurring on both the upper ends and inner and radial walls of pericentral and subcortical cells. In C. dasyphylla the thickenings occur as band-like caps on upper ends of these cells. Older pericentral cells may also develop additional, separate thickenings on the inner and radial walls, and in cells near the base of the plant these become lobed.

The production of an auxiliary cell after fertilization of the procarp has been observed in both species. However its purported absence in material of C. tenuissima examined by Phillips (1896, p. 19) is not discounted as this situation has been observed in a number of southern Australian species of Chondria in which the division of the supporting cell is delayed until after the diploid nucleus has been transferred from the carpogonium. This variation appears to be more common in the Ceramiales than previously realized, however it does not appear to be sufficient to invalidate Kylin's differentiation of the order.     

Occurrence and distribution of tracheoidal elements in the Orchidaceae

Eighty-eight species of West African orchids were examined for tratheoidal elements in the root, stem, pseudobulb and leaf. Forty-three species (49%) contained tiacheoidal elements. al were epiphytic species; none of the twelve terrestrial and one epilithic/terrestrial species examined contained tracheoidal elements. Of the epiphytic species, twenty-one contained tracheoidal elements in the roots; seventeen in the stem/pseudobulb and twenty-three in the leaves.
The tracheoidal elements are similar in structure: they all possess annular, spiral, reticulate or pitted secondary wall thickenings. These elements vary in shape, size and distribution in the different species and these variations may be of some taxonomic use within the Orchidaceae.
The functions of the tracheoidal elements is not clear, but they probably provide mechanical support and also aid water -retention in the organs containing them.     

ENDOTHECIUM IN IRIDACEAE AND ITS SYSTEMATIC IMPLICATIONS

An examination of the endothecial thickenings in 44 species of Iridaceae, selected from the four subfamilies and all major tribes, provides useful information about generic and tribal relationships in the family. U-shaped thickenings occur in Nivenioideae and Iridoideae—Sisyrinchieae, the latter the least specialized tribe of its subfamily. The occurrence of helical thickenings in all members examined of Iridiodeae tribes Irideae, Mariceae, and Tigridieae (a putatively monophyletic group) and Ixioideae is consistent with the recognition of these two lines as distinct taxa based on anatomical, morphological, phytochemical, and in the case of Ixioideae, palynological criteria. Baseplate thickenings are restricted to Patersonia. However, the shrubby Cape genera—Nivenia, Klattia, and Witsenia—have U-shaped thickenings which show a tendency for the bars on the inner periclinal cell walls to anastomose, suggesting a trend towards the baseplate condition in Patersonia. This accords with a suggested relationship between these genera, based on anatomical and flavonoid similarities. The pattern of variation in endothecial thickenings in Iridaceae is consistent with the phylogeny proposed by Goldblatt (1990). The distribution of thickening types within the family does not make it possible to polarize this character, but the most parsimonious interpretation assumes that U-shapes are basic. However, in at least some other monocotyledonous families the pattern suggests that U-shaped thickenings are derived from helices.     

Studies on the Pollen Morphology and Seed Coat of the Genus Cistanche (Orobanchaceae) in China

In the present paper pollen grains of 5 species and seed coat of 4 species of the genus Cistanche (Orobanchaceae) from China were examined by scanning electron microscope As a result, two types of the pollen exine sculpture are distinguished: (1) tuberculate, C. salsa and C. lanzhouensis; (2) rugulate or fine reticulation formed by the fusion of rugae, C. sinensis, C. deserticola and C. tubulosa. Chinese Cistanche was classified into two sections based on the gross morphology by the present author (Zhang, 1984). C. lanzhouensis and C. sinensis were included in one section. This classification is in conflict with the pollen type, which indicates that the characters of pollen grains and external morphology in this genus have evolved at different rates. The differences in pollen morphology of Chinese Cistanche can serve as characters for delimitating species. According to our abservation, C. lanzhouenis Z. Y. Zhang differs from the other members of Cistanche not only in external morphology but also in pollen morphology. Pollen grains are subprolate in this species, while prolate in the other four species, and exine sculpture is tuberculate. The present study provides the establishment of this new species (Zhang, 1984) with palynological evidence. The seed coat sculpture in Chinese Cistanche are constantly alveolate, but there are some slight differences, by which the sculpture can be divided into two types: (1) testa cells have or have not thickenings on the inner anticlinal walls; cavernulous sculpture is present on outer periclinal wall of some cells: C. sinensis; (2) testa cells have striate thickenings on the inner anticlinal walls: C. salsa, C. deserticola and C. tubulosa. The characters of seed coatof some significance for the delimitation of species.     

10 种茶藨子属植物导管分子形态特征及其生态适应性比较研究简

利用光学显微镜和扫描电子显微电镜,以10种茶藨子属植物为研究材料,观察了其导管分子的形态结构。结果显示：（1）所研究的茶藨子属植物导管分子穿孔板为梯状穿孔板,且穿孔板上横隔分布的数量不同,端壁倾斜角度种间变化不大;（2）导管分子纹孔式样为互列式或兼有互列式和对列式,纹孔形状种间存在差异;（3）有的种类导管分子内壁有螺纹加厚或网状凸起。研究表明,不同生境下的茶藨子属植物导管形态与其生态适应性之间有较强的相关性,表现为湿生环境的物种导管较短,直径较宽;旱生环境的物种导管较长,直径较小;中生环境的居中。本文分析了茶藨子属植物导管分子形态特征的生态适应性。     

Anatomical Characteristics of the Stem of Sigillaria cf. brardii from Coal Balls in Guizhou Province,China

The stem specimens of Sigillaria cf. brardii were collected from the coal balls of Upper Permian in Shuicheng Coal Mines in Guizhou Province. The main anatomical characteristics of Sigillaria cf. brardii are described as follows: The stem is siphonostelic, with pith composed entirely of polygonal parenchyma cells, there are secondary walls in some pith cell cavities these secondary walls show the characters of cell division. Surrounding the pith is the continuous cylindrical primary xylem which consists entirely of tracheids. The outermost, and part are the protoxylem elements show spiral secondary thickenings. In cross section, the outer edge of exarch primary xylem appears regularly sinuous, with trace of mesarch leaf originating from the furrows. The centripetal metaxylem is characterized by scalariform wall thickenings on the tracheids, and delicated strands of secondary wall materials extending between abjacent bars, these structures are called fimbris, or williamson striations, and are characteristic in lepidodendrids. The secondary xylem consists of tracheids and vascular rays. The tracheids, too, have scalariform wall thickenings and fimbris. The rays are one-to twocell width and several to more than ten cells in height.     

扁圆封印木（相似种）茎干的解剖特征

贵州省水城矿区晚二叠世煤核中扁圆封印木（相似种Ｓｉｇｉｌｌａｒｉａ ｃｆ．ｂｒａｒｄｉｉＢｒｏｎｇｎ．）茎干的主要解剖特征如下：管状中柱,具多边形薄壁细胞组成的髓。初生木质部成环带状,外缘呈规则的齿槽状,向心式发育。次生木质部显束状特征,横切面管胞为方圆至长方形,纵切面为梯状壁增厚,并具流苏纹。射线１—２列细胞宽,数个至十余个细胞高。叶迹起源于初生木质部外缘的槽中,中始式,但以向心发育为主。     

A SYSTEMATIC STUDY OF ENDOTHECIAL THICKENINGS IN THE ORCHIDACEAE

Endothecial cell thickenings were examined in anther macerations of representative species from 210 genera of the Orchidaceae. Nearly all species examined possessed the characteristic thickened walls which, in several tested species, gave a positive reaction to phloroglucinol, indicating the presence of lignin. Four basic thickening types were identified; distribution of the types was found to be largely in agreement with previously recognized suprageneric groups. Type I thickenings are tightly packed channels of loops or helices and were found in the “neottioid” genera, the Apostasioideae, and putatively basal genera in the remaining subfamilies. Because of its occurrence in the Apostasioideae, which is believed to be the most basal subfamily, Type I is hypothesized to be the plesiomorphic thickening type for the remainder of the Orchidaceae. Type II thickenings appear as scattered loops and may be a synapomorphy for the Orchidoideae, as they were found in all genera sampled from the subfamily except Disperis. Type III thickenings are circular in appearance and were found in the Cypripedioideae and in some members of the Spiranthoideae and Epidendroideae. Type IV thickenings show little regular arrangement, appearing to be scattered bars, and were observed primarily in the Epidendroideae and also in some Spiranthoideae. Three subtypes were recognized in Type III and Type IV. Some genera, such as Triphora, Goodyera, and Elythranthera, had thickenings that appeared intermediate between the recognized types. In general, terrestrial genera were found to have regularly arranged, well-developed thickenings, while many epiphytic groups showed congested, irregular, thinner thickenings.     

Evaluation of the Spiral Plate Maker for the Enumeration of Micro-organisms in Foods

A statistically based comparison of five methods of enumerating bacteria in foods has been undertaken to assess the potential application of the Spiral Plate Maker (Gilchrist et al. 1973) which is claimed to reduce very significantly the costs involved in the quantitative estimation of viable micro-organisms in foods. The performance of the Spiral Plate Maker was compared with that of three conventional methods (pour plate, surface spread plate and drop count) for the examination of four types of food by four different operators. Analysis of variance showed that there were no differences between the methods at the 5% level although some isolated interactions occurred. Regression and correlation coefficients between the various methods were all highly significant and the results obtained by the spiral plate method were within the limits of error for traditional quantitative methods. The spiral plate method, in many cases, can replace advantageously any of the other methods for the quantitative estimation of viable microorganisms in foods. Labour requirements for the enumeration of micro-organisms by the spiral plate method were only 31% of that required for one conventional method. In addition considerable savings in materials were achieved.     

MODIFIED REMNANTS OF CENTRIPETAL XYLEM IN THE LEAF TRACE OF CEPHALOTAXUS

A study of the leaf traces at the nodes in various species and varietal forms of Taxus, Torreya, Amentotaxus and Cephalotaxus reveals, only in Cephalotaxus, an unusual type of parenchymatous tissue associated with the xylem of the leaf trace. The cells of this tissue occur in one to three layers, have abundant cytoplasm and conspicuous nuclei. The thin walls of these cells are devoid of pits and show spiral or spiral-reticulate thickenings. These thickenings, although readily taking the counterstain, reveal the presence of lignin as determined by the phloroglucin test and by fluorescence microscopy. This tissue is always internal—that is, adaxial—to the protoxylem of the trace. From the node it accompanies the trace for a short distance into the leaf base, where it gives way centrally to the typical leaf parenchyma and laterally to the transfusion tissue on the flanks of the bundle. In the basipetal direction it is in contact with the inner face of the annular protoxylem of the stele, eventually disappearing in the typical pith parenchyma. This tissue occasionally reveals instances of well-lignified tracheid-like centripetal elements. On the basis of the characteristics of this tissue, it is suggested that its origin lies in former centripetal xylem. The significance of this tissue to the evolution of the stele and the systematic position of Cephalotaxus is discussed.     

"Spiral asters" and cytoplasmic rotation in sea urchin eggs: induction in Strongylocentrotus purpuratus eggs by elevated temperature

"Spiral asters" composed of swirls of subcortical microtubules were recently described in fertilized eggs of the sea urchin Strongylocentrotus purpuratus. In our study, these structures did not occur at culture temperatures below 16 degrees C. When the culture temperature was elevated, however, "spiral asters" routinely appeared during a susceptible period before mitotic prophase when the sperm aster-diaster normally exists. A massive and protracted rotation of the cytoplasm (excluding an immobile cortex and perinuclear region) began within 1 min of exposure to elevated temperature. Fibrils of the "spiral aster" could be seen within this rotating mass even by bright-field microscopy. The identity of microtubules in these structures was confirmed by indirect immunofluorescence microscopy. A mechanistic association between "spiral aster" formation and cytoplasmic rotation was indicated by the simultaneous inhibitory effects of microtubule and dynein poisons. Inhibitors of microfilaments, however, had no effect. We infer that elevated temperature induces unique changes in the microtubules of the pre-prophase sperm aster-diaster, resulting in cytoplasmic rotation and the spiral configuration of microtubules. Comparative cytological evidence supports the idea that "spiral asters" do not normally occur in fertilized sea urchin eggs. Biogeographic evidence for S. purpuratus indicates that fertilization and development naturally occur below 15 degrees C, hence "spiral asters" in eggs of this species should be regarded as abnormalities induced in the laboratory by unnaturally elevated temperatures.     

A new species of camallanidae from Ageneiosus ucayalensis (Pisces: Siluriformes) from Pará State, Brazil

Procamallanus (Spirocamallanus) belenensis n. sp. is described using light and scanning electron microcopy, based on specimens taken from Ageneiosus ucayalensis, Castelnau, 1855 (Pisces: Siluriforme), a freshwater fish commonly called mandubé, in Pard State, Brazil; Procamallanus (Spirocamallanus) rarus is recorded from the same host. To our knowledge there are no previous reports of nematodes from this fish species. Procamallanus (S.) belenensis is characterized by the presence of 8-13 cuticular spiral thickenings coating 2/3 of posterior region of the buccal capsule of males and females (the anterior third is smooth); small sub-equal spicules; 3 and 4-5 pairs of pre- and post-cloacal papillae, respectively; the proportion of muscular and glandular esophagus is 1:1.5-2; males present 2 spike-like projections at the tail tip, which are absent in females by light microscopy. The most closely related species are Procamallanus (Spirocamallanus) inopinatus and Procamallanus (Spirocamallanus) pintoi. The new species differs from the most closely related species by the presence of 8-10 cuticular spiral thickenings in the buccal capsule of males and 9-13 in the females, 8 pairs of male clocal papillae (3 pre- and 5 post-cloacal, respectively), and only males bearing 2 minute, spike-like projections at the posterior end.     

STEEREELLA,A NEW GENUS OF HEPATICAE FROM THE WEST INDIES

In addition to the complete lack of the usual spiral bands of thickenings in the elaters, the new genus Steereella is unique among the Hepaticae for the resemblance of its cellular organization in the thalloid gametophyte to that of some moss leaves. The taxon recognized is one genus, Steereella, gen. n., and one species S. linearis (Swartz) Kuwah. comb. nov., in which the variable nature of the gametophyte is particularly noted. The genus appears to be restricted to the West Indies.     

The Micromorphology of Pit Membranes in Tracheary Elements of Ericales: New Records of Tori or Pseudo-tori?

BACKGROUND AND AIMS: Intervascular pit membranes were examined within Ericales to determine the distribution and structure of torus-like thickenings. METHODS: Forty-nine species representing 12 families of the order Ericales were investigated using light, scanning and transmission electron microscopy. They were compared with four species of Oleaceae to determine the true nature of the thickenings. KEY RESULTS: Pit membranes with torus-like thickenings were observed in seven species of Ericaceae and were found to be amorphous, plasmodesmata-associated structures with an irregular distribution. These pseudo-tori show major differences compared with true tori with respect to their distribution and ultrastructure. Genuine tori, which are strongly correlated with round pit apertures in narrow tracheary elements, were found in two species of Osmanthus (Oleaceae). CONCLUSIONS: The pseudo-tori found in some Ericaceae are considered to be similar to pit membrane thickenings previously recorded in Rosaceae. While true tori appear to be functionally significant in terms of efficiency and safety of water transport, the possible function of pseudo-tori could be associated with the role of plasmodesmata during differentiation of tracheids, fibre-tracheids or narrow vessels.     

Oguraxylon,a new genus belonging to the family taxodiaceae,from the cretaceous of Hokkaido

Described is a new species belonging to a new genus of petrified wood,Oguraxylon yubariense sp. nov. It exhibits characteristics of the Taxodiaceae in general anatomy and closely resemblesTaxodioxylon sequoianum andT. albertense. It is, however, unique in having tertiary spiral thickenings on the walls of the tracheids, which have never yet been found in any extent or extinct species of the family.     

Murine CMV-Induced Hearing Loss Is Associated with Inner Ear Inflammation and Loss of Spiral Ganglia Neurons

Congenital human cytomegalovirus (HCMV) occurs in 0.5–1% of live births and approximately 10% of infected infants develop hearing loss. The mechanism(s) of hearing loss remain unknown. We developed a murine model of CMV induced hearing loss in which murine cytomegalovirus (MCMV) infection of newborn mice leads to hematogenous spread of virus to the inner ear, induction of inflammatory responses, and hearing loss. Characteristics of the hearing loss described in infants with congenital HCMV infection were observed including, delayed onset, progressive hearing loss, and unilateral hearing loss in this model and, these characteristics were viral inoculum dependent. Viral antigens were present in the inner ear as were CD3+ mononuclear cells in the spiral ganglion and stria vascularis. Spiral ganglion neuron density was decreased after infection, thus providing a mechanism for hearing loss. The lack of significant inner ear histopathology and persistence of inflammation in cochlea of mice with hearing loss raised the possibility that inflammation was a major component of the mechanism(s) of hearing loss in MCMV infected mice.     

Histochemistry, ultrastructure and possible significance of dead parenchyma cells with specialized walls in the leaf and rhizome of Sansevieria

Abstract. The internal parenchyma of the leaf and rhizome in 36 species of Sansevieria is made of dead cells and living cells arranged in a regular pattern. Intercellular spaces are lacking. The walls of dead cells consist of an inner amorphous layer positive to the fluorescence test for callose, a middle suberin-like layer and an outer fibrillar layer. In about half of the species examined, the inner layer forms distinctive thickenings. Detached leaves of Sansevieria lose water very slowly, and are able to recover it quickly. The pattern of leaf dehydration appears to be related to leaf morphology, whereas no relation is evident between the pattern of leaf rehydration and leaf morphology. Neither leaf dehydration nor leaf rehydration pattern is affected by the presence of wall thickenings in the dead parenchyma cells. The fresh weight per unit volume of both turgid and droughted leaves is nearly 1, denoting that the dead cells are filled with water and do not undergo substantial cavitation during drought. The data indicate that the dead parenchyma cells of Sansevieria are a specialized water-storing system.