翼萼蔓属系统位置的研究

对翼萼蔓属进行了外部形态、花部解剖学、大小孢子发生和雌雄配子体发育、花粉形态和染色体 的研究,并以此为据,讨论了该属的分类等级和系统位置。翼萼蔓属的花具花冠腺体。花萼筒具16条 维管束,花冠筒具12条维管束,二者的维管束是独立发生的。每心皮具1条背维管束和2条腹维管束。 雄蕊先熟。花药四室;药壁发育为双子叶型;绒毡层异型起源,细胞具双核,属腺质型绒毡层;一层中层 细胞;药壁表皮层宿存,细胞膨大,细胞壁纤维状加厚;药室内壁部分纤维状加厚。小孢子母细胞减数分 裂的胞质分裂为同时型;成熟花粉为3-细胞型。子房为2心皮,1室,超侧膜胎座;胚珠25～40列,倒生 胚珠,腹维管束靠近腹缝线。薄珠心,单珠被。大孢子母细胞减数分裂形成的4个大孢子呈直线式排 列,其中合点端的大孢子具功能。胚囊发育为蓼型。极核在受精前融合为次生核,反足细胞3个,具反 足吸器。胚乳发育为核型。花粉球形,极轴长约32.8μm,赤道轴长约34.2μm,外壁纹饰为网状纹 饰。体细胞染色体数为2n=26,染色体基数为x＝13,核型公式为2n＝26＝18m＋4sm+2st＋2t,属 2A型。比较翼萼蔓属、蔓龙胆属和扁蕾属的外部形态、花部解剖学、胚胎学、花粉形态和染色体特征,表 明翼萼蔓属和扁蕾属可能具较近的亲缘关系,起源于一个较早的共同祖先。在分类等级上,把翼萼蔓属作为一独立属处理较为合适。     

澜沧荛花(瑞香科)的花部形态发生yh及其系统学意义(英文)

通过扫描电镜对澜沧荛花Wikstroemiadelavayi花部的形态发生过程进行了观察和分析 ,旨在为该属的系统学研究提供花部发育形态学资料。澜沧荛花花部的发生和早期发育呈远轴面向近轴面的顺序 ,但这一式样由于近轴面的器官在早期发育之后生长加速发生了转变。因此 ,花开放时所表现的所谓辐射对称 ,显然是由同一轮器官的异率生长所导致的次生现象。花盘发生于花萼筒基部的远轴面上 ,与花萼、雄蕊的发生间隔时间较长。花盘原基在下轮雄蕊着生处凹陷或间断 ,与之相对应 ,花盘裂片与下轮雄蕊呈互生。由此 ,花盘显然不是花托的一部分 ,也不是象花萼、雄蕊和心皮一样的独立结构 ,将其解释为雄蕊群的一部分更合理。花盘的发生和早期发育及其着生位置同其他花部器官的发生和发育式样具有明显的相关性 ,这种相关性对进一步阐明瑞香属Daphne和荛花属Wikstroemia的系统发育关系具有一定意义。根据对雌蕊群的发生和发育过程观察 ,该种的子房是由一个近轴面的可育心皮和一个远轴面的不育心皮融合而成的单室子房 ,为假单心皮雌蕊。尽管荛花属和瑞香属均属于单室子房 ,但澜沧荛花的子房维管束中的腹束排列于中轴位置 ,而目前资料显示瑞香属植物的腹束接近于侧膜位置 ,这方面仍需进一步研究     

舞花姜花部维管束系统的解剖学研究

对舞花姜(Globba racemosa)花部维管束系统进行解剖学观察分析,以探讨其缺失雄蕊的去向及其唇瓣和腺体结构的属性.结果显示:(1)舞花姜花梗部的维管束分散排列在基本组织内.(2)子房基部的维管束排成2部分,中央区为分散排列的小维管束,外方为一轮大维管束环,且外环维管束发育为子房壁维管束,心皮背束和隔膜束均起源于中心区维管束,二者的分支在延长部形成一个维管束网结;在网结之上,近轴面的两束心皮背束分支分别进入到2枚侧生退化雄蕊中并成为其主束,远轴面心皮背束的内方分支则成为唇瓣中束,三束心皮背束的其余分支均上行入萼片.(3)唯一1枚功能雄蕊接受近轴面隔膜束的内方主支作为其主束,远轴面2枚隔膜束的主支最后进入唇瓣的两侧束,三束隔膜束的外分支均发育为花瓣束.研究认为:舞花姜的唇瓣是一个三重结构,其中央维管束代表1枚外轮雄蕊,两侧维管束则分别代表2枚内轮雄蕊;舞花姜的2枚花瓣状退化雄蕊与唇瓣的中央一起构成外轮雄蕊,唯一1枚可育雄蕊和唇瓣的两侧同属内轮雄蕊.本研究结果支持姜科子房延长部形成的腺体属于子房上部心皮边缘的维管化附属物的观点.     

澜沧荛花(瑞香科)的花部形态发生 及其系统学意义

通过扫描电镜对澜沧荛花Wikstroemia delavayi花部的形态发生过程进行了观察和分析,旨在为该属的系统学研究提供花部发育形态学资料。澜沧尧花花部的发生和早期发育呈远轴面向近轴面的顺序,但这一式样由于近轴面的器官在早期发育之后生长加速发生了转变。因此,花开放时所表现的所谓辐射对称,显然是由同一轮器官的异率生长所导致的次生现象。花盘发生于花萼筒基部的远轴面上,与花萼、雄蕊的发生间隔时间较长。花盘原基在下轮雄蕊着生处凹陷或间断,与之相对应,花盘裂片与下轮雄蕊呈互生。由此,花盘显然不是花托的一部分,也不是象花萼、雄蕊和心皮一样的独立结构,将其解释为雄蕊群的一部分更合理。花盘的发生和早期发育及其着生位置同其他花部器官的发生和发育式样具有明显的相关性,这种相关性对进一步阐明瑞香属Daphne和荛花属Wikstroemia的系统发育关系具有—定意义。根据对雌蕊群的发生和发育过程观察,该种的子房是由一个近轴面的可育心皮和一个远轴面的不育心皮融合而成的单室子房,为假单心皮雌蕊。尽管荛花属和瑞香属均属于单室产房,但澜沧荛花的子房维管束中的腹束排列于中轴位置,而目前资料显示瑞香属植物的腹束接近于侧膜位置,这方面仍需进一步研究。     

澜沧尧花（瑞香科）的花部形态发生及其系统学意义

通过扫描电镜对澜沧荛花Wikstroemia delavayi花部的形态发生过程进行了观察和分析,旨在为该属的系统学研究提供花部发育形态学资料.澜沧荛花花部的发生和早期发育呈远轴面向近轴面的顺序,但这一式样由于近轴面的器官在早期发育之后生长加速发生了转变.因此,花开放时所表现的所谓辐射对称,显然是由同一轮器官的异率生长所导致的次生现象.花盘发生于花萼筒基部的远轴面上,与花萼、雄蕊的发生间隔时间较长.花盘原基在下轮雄蕊着生处凹陷或间断,与之相对应,花盘裂片与下轮雄蕊呈互生.由此,花盘显然不是花托的一部分,也不是象花萼、雄蕊和心皮一样的独立结构,将其解释为雄蕊群的一部分更合理.花盘的发生和早期发育及其着生位置同其他花部器官的发生和发育式样具有明显的相关性,这种相关性对进一步阐明瑞香属Daphne和荛花属Wikstroemia的系统发育关系具有一定意义.根据对雌蕊群的发生和发育过程观察,该种的子房是由一个近轴面的可育心皮和一个远轴面的不育心皮融合而成的单室子房,为假单心皮雌蕊.尽管荛花属和瑞香属均属于单室子房,但澜沧荛花的子房维管束中的腹束排列于中轴位置,而目前资料显示瑞香属植物的腹束接近于侧膜位置,这方面仍需进一步研究.     

圆瓣姜花花部维管束解剖及其系统学意义

用石蜡切片技术研究了圆瓣姜花(Hedychium forrestii Diels)的花部维管束系统解剖结构,探讨了同源异形的各轮花器官维管束来源和属性.结果表明,圆瓣姜花的2枚花瓣状结构为外轮雄蕊成员;唇瓣是三重结构,其中脉源十1枚外轮雄蕊维管束系统,两侧脉源于2枚内轮雄蕊维管束系统;上位腺体为隔膜蜜腺.本研究支持Thompson和Gregory关于姜科唇瓣是三重结构的观点;与其他姜科植物一样,圆瓣姜花子房延长部形成的上位腺体属于隔膜蜜腺而不是雄蕊成员.与已研究过的姜花属植物比较,姜花属花器官维管束系统的来源与走向是一致的,同源异形现象在姜花属植物花的进化中扮演极为重要的角色,可为解释花器官属性提供重要线索.     

焕镛木属——中国木兰科一新属

焕镛木属(Woonyoungia Law)曾分布于广西西北部罗城县,现星散分布于广西北部环江县,贵州省东部荔坡县、云南西南部马关县、是珍稀濒危树种。焕镛木属的花单性异株,与木兰科其他各属均不同;雄花的花被片形态相似而雌花的花被片则明显异形,这也是与木兰科其他各属均不同。此外,焕镛木属的雄蕊两药室稍分开,内侧向开裂,药隔伸出成舌状尖;雌蕊6-9,心皮全部合生,仅露出柱关面;成熟心皮革质,沿背缝开裂,形成近球形的聚合果。与它近缘的单性木兰属(Kmeria Dandy)则雄蕊两药室紧贴,内向开裂,顶端钝,药隔不伸出;成熟心皮木质、沿腹缝全裂及顶端开裂,最后裂成两果瓣、形成各成熟心皮散开的聚合果等不同。依上述不相同特征,故成立焕镛木属属新属。     

南天竹属的花部器官发生及其系统学意义

报道了南天竹（ＮａｎｄｉｎａｄｏｍｅｓｔｉｃａＴｈｕｎｂ．）（小檗科）的花部器官发生。发现该属植物萼片、花瓣和雄蕊的发生式样为三数轮生;雄蕊与花瓣是经它们所具有的共同原基进行侧向分裂而形成的;花瓣发育早期存在迟滞发育的阶段;心皮发生属于瓶状发生类型。讨论了花器官的三基数性质,小檗科花瓣的来源,雄蕊对瓣着生及单心皮雌蕊的形成等问题。对本属的花部个体发育性状同小檗科中已有报道的红毛七属（Ｃａｕｌｏｐｈｙｌｕｍ）、足叶草属（Ｐｏｄｏｐｈｙｌｕｍ）进行了比较,萼片多数轮列与心皮发生的多态现象是南天竹属的独特性状。     

里普草属—中国茜草科一新纪录属

里普草属——Leptunis Stev。一年生草本植物。茎细弱,常茎中部分枝,枝细线状,圆柱形,无毛。叶轮生,全缘,无托叶,线状。花两性,辐射对称,花冠管状;无花萼;雄蕊4枚;子房二室;柱头二裂,柱头裂片球形;果为小坚果,常双生。     

大麦亚族3属植物的叶片解剖特征及其系统关系

采用石蜡切片法对大麦亚族中新麦草属、芒麦草属和三柄麦属主要代表种的叶片横切面形态学特征进行观察。结果显示:(1)大麦亚族3属植物的叶片均为等面叶,由表皮、叶肉和维管束三部分构成,表现为典型的狐茅型,即下表皮细胞形状、大小和排列均匀,上表皮细胞形状、大小和排列不均,叶肉无栅栏组织和海绵组织之分,具有双层维管束鞘,周围叶肉细胞呈不规则排列,厚壁组织与表皮相接;但3属植物在上表皮的凹凸程度,下表皮细胞壁的厚薄,叶肉组织中部束间厚,大小型维管束的数目、中肋维管束横径等叶片横切面特征上存在明显差异。(2)根据3属植物叶片横切面性状的演化趋势,对各属的演化关系和系统位置分析表明,新麦草属最原始,芒麦草属较进化,三柄麦属最高级;新麦草属可能直接派生了较进化的芒麦草属,并在芒麦草属的基础上进而产生了最高级的三柄麦属;新麦草属、芒麦草属和三柄麦属的这一系统关系与利用外部形态特征所获得的演化趋势基本一致。     

Nodal and leaf anatomy of Xanthophyllum (Polygalaceae)

The nodal anatomy of Xanthophyllum is unilacunar with a single broad trace departing the cauline stele. The "stipular glands" or extra floral nectaries of some species are vascularized by bundles originating from the base of the leaf trace. Considerable variation exists among species in petiole vasculature with siphonosteles, steles with medullary bundles and simple, flat traces present. The lamina also shows variation in the presence or absence of a hypodermis, nature of vein sheathing, presence or absence of abaxial epidermal papillae, amount of intercellular spaces, and mature stomatal patterns which range from anisocytic and paracytic to those in which no subsidiary cells are discernible. Of nearly uniform occurrence throughout the genus are extraordinary tracheoid foliar idioblasts, which are confined to the veins in terminal or subterminal positions. The large amount of variation in leaf anatomy is shown to be taxonomically significant within the genus.     

Embryology of Megacodon stylophorus and Veratrilla baillonii (Gentianaceae): descriptions and systematic implications

The embryological characters of Megacodon stylophorus (C. B. Clark) H. Smith and Veratrilla baillonii Franch. are described for the first time and the systematic relationships of Megacodon and Veratrilla are discussed. Both species share the following embryological features. The anthers are tetrasporangiate. The formation of anther walls is of the Dicotyledonous Type. The tapetum is of glandular type with uninucleate cells which have a dual origin. The tapetal cells on the connective side show radial elongation or periclinal division and intrude into the anther locule to form 'placentoids'. Cytokinesis in the microsporocyte meiosis is of the simultaneous type and the microspore tetrads are nearly always tetrahedral, rarely decussate. The ovary is bicarpellate and unilocular. The ovule is unitegmic and tenuinucellar. The formation of the embryo sac is of the Polygonum Type. Before fertilization, the two polar nuclei fuse into a secondary nucleus. Fertilization is porogamous. The development of the endosperm is of the Nuclear Type. However, the two species show variation in the following features: the number of cell layers which form the anther locule wall; construction of the wall of the mature anther; cell number in mature pollen grains; ovule number in cross sections of placentae; degree of ovule curvature; character of the hypostase and seed shape. In a comparison with the other taxa in the tribe Gentianeae using embryological features, Megacodon is referred to as an independent genus and should be treated as a member of the subtribe Swertiinae; Veratrilla is better separated from Swertia s . l . as an independent genus. Veratrilla is more derived than Swertia s . s. and shows a close relationship with S. tetraptera . © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 317–331.     

Morphological studies on the genusClematis Linn

The basic pattern of the vascular supply to stamens and carpels in the flowers ofClematis is discussed on the basis of serial sections. The bundles of the receptacular stele show fairly regular fusions and divisions in relation to the origin of the vascular supply, giving off a single trace for each stamen or carpel. In many cases the trace arises by the trifurcation of the “fused bundle” and the subsequent departure of the median strand. This is the pattern basic to the structure of the receptacular stele of the genus. Although the basic pattern involves a variety of modifications, each of the diverging traces fundamentally leaves a single independent gap in the stele, contrary to the conclusion of previous authors. Similarities and differences between a group of stamens and carpels and that of sepals and foliage leaves are also discussed based on the results of the present and previous studies on the vascular anatomy of the floral receptacle and the inflorescence axis.     

MORPHOLOGICAL STUDIES OF THE NYMPHAEACEAE SENSU LATO. XVII. FLORAL ANATOMY OF ONDINEA PURPUREA SUBSPECIES PURPUREA (NYMPHAEACEAE)

Classification and phylogeny of the Nymphaeaceae are unresolved. This study provides floral anatomical data that will assist in elucidating generic interrelationships and systematic relationships to other taxa of angiosperms. The floral anatomy of Ondinea purpurea den Hartog subsp. purpurea has been examined utilizing light microscopy. The peduncle possesses stelar vascular bundle complexes and cortical vascular bundles. Cortical bundles terminate within the peduncle. Each bundle complex consists of 2 collateral bundles on the same radius, the inner bundle inverted; 2 protoxylary lacunae occur yet differ in structure and function. Progressing acropetally, the inner xylary lacunae become discrete mesarch strands surrounded centrifugally by a vascular cylinder formed by divisions and anastomosing of the bundle complexes. Together these become the massive receptacular vascular plexus. The plexus provides collateral traces to the floral organs. Each sepal receives 3 traces that separate from the plexus as 1–3 lateral traces. Petals are absent and no vestigial petal traces have been observed. Distally, the plexus forms several large strands of connate gynoecial and androecial traces termed the principal vascular bundles (PVBs). Ventral veins separate from the PVBs and the latter extend acropetally through the outer ovary wall. Branches of the ventrals and PVBs contribute to septal vascular reticula from which each ovule is supplied by one vascular bundle. Each stamen receives 1 trace from branches of the PVBs. The ventrals and PVBs terminate within the carpellary lobes. A comparative anatomical study is offered that supports the inclusion of Ondinea in the Nymphaeaceae sensu stricto.     

THE FLORAL ANATOMY OF KOEBERLINIA ZUCC: SYSTEMATIC IMPLICATIONS

The in toto pattern of the floral vasculature in Koeberlinia Zucc, is distinctive. The median vascular trace to each sepal is concrescent with the antesepalous stamen trace forming a trace complex. Each petal trace is concrescent with the nearest antestaminal trace, and this common trace is in turn concrescent basally with the common basal supply to the adjacent sepal margins. The ventral carpellary bundles and the ovular traces of the two carpels are arranged for part of the ventral carpellary system into an essentially continuous hollow stele-like cylinder and many of the ovular vascular supplies originate from this strand. All vascular concrescences are congenital. Comparisons of the morphological and floral vasculature characters of Koeberlinia with those of its various putative allies revealed that there are no substantial reasons for linking Koeberlinia with Canotia, Celastraceae, Rutaceae, Simaroubaceae, or Zygophyllaceae. The in toto floral vascular structure of Koeberlinia is closely similar to that of the Caryophyllaceae and dissimilar to that of the Capparaceae. Several qualitative characters of the secondary xylem of Koeberlinia differ from those of the Capparaceae, yet certain important ones are similar. Many of the morphological characters of Koeberlinia are similar to those of the Capparaceae as well as the Caryophyllaceae, yet certain critically important ones strongly indicate a relation of Koeberlinia to the Capparaceae: occurrence of myrosin cells, capparaceous pollen, capparaceous ovular characters. To include Koeberlinia within either of these families is unwise, but the writers are inclined to retain Koeberlinia in a monogeneric family within the larger Capparales.     

FLORAL ANATOMY IN THE SAXIFRAGACEAE SENSU LATO. II. SAXIFRAGOIDEAE AND ITEOIDEAE

The floral anatomy and morphology of 26 species from the Saxifragoideae and three from the Iteoideae are described and compared. The flowers of the Saxifragoideae are predominantly actinomorphic, partially epigynous and/or perigynous, and pentamerous, with two carpels which bear numerous ovules. There is usually some degree of independence between carpels, and the normally separate styles possess both a canal and transmitting tissue. Generally, staminodia are absent and nectariferous tissue, which is not vascularized, is present. The subfamily is characterized by large multicellular trichomes with globular, often glandular, heads. Placentation may be parietal, axile, or transitional between the two; parietal appears to be a derived condition in the subfamily. The vascular cylinder in the pedicel generally consists of several to many discrete bundles from which diverge ten compound traces at the base of the receptacle, leaving an inner cylinder of vascular strands that coalesce at a higher level into either as many ventral bundles as carpels or twice that number. In the former case, each ventral bundle consists of one-half of the vascular supply to each adjacent carpel and separates into individual ventral strands in the distal half of the ovary. The ventral bundles provide vascular traces to the ovules and, along with the dorsals, extend up the style to the stigma. Each trace diverging in a sepal plane typically supplies one or more carpel-wall bundles, a median sepal bundle, and a stamen bundle. Each petal-plane trace usually provides one or more carpel-wall bundles, a lateral trace to each adjacent sepal, a petal bundle and, in flowers with ten stamens, a stamen bundle. Dorsal carpel bundles are usually recognizable and may originate from traces in either perianth plane. While the position of Ribes remains problematical, its floral structure does not easily exclude it from the Saxifragoideae. Floral structure in the Iteoideae is remarkably similar to that in the Saxifragoideae, the main differences being a lesser degree of independence between carpels, generally narrower placentae with somewhat fewer ovules, and the presence of only unicellular, acutely pointed epidermal hairs as opposed to the relatively complex, multicellular trichomes prevalent in the Saxifragoideae.     

The floral nectaries in theIrvingiaceae

TheIrvingiaceae generally possess large intrastaminal receptacular disc nectaries of the mesenchymatic histo-type, which receive numerous small phloematic bundles directly from the central stele. The non-glandular epidermis bears some 10 to 15 strictly localized stomata that are deeply sunken in the parenchyma. The nectar is assumed to be exposed on the disc surface. Flowers are of simple construction, lacking specialized organs to attract pollinators. A wide range of pollinators is thus expected. TheIrvingiaceae have more characters in common withSimaroubaceae thanIxonanthaceae and should therefore be retransferred as a family of their own next toSimaroubaceae. The floral nectaries of theGeraniales and their systematic implications V. For the fourth part seeLink (1992)     

A New Species of Millerocaulis (Osmundaceae) from the Lower Cretaceous of California

A small permineralized osmundaceous stem has been collected from marine sediments of the Early Cretaceous (Aptian), Upper Chickabally Member of the Budden Canyon Formation near Ono, California. The specimen, 8.5 cm long and 5.4 cm wide, represents a stem surrounded by a mantle of stipular leaf bases and adventitious roots. A large number of sections were studied through the use of the cellulose acetate peel technique. The stem was erect, 11x13 mm in diameter, with a parenchymatous pith and two-layered cortex. The stele is an ectophloic siphonostele with 65-79 leaf traces in the stem per cross section. Leaf gaps are only produced in 13% of the departing traces. Most leaf traces have "delayed" gaps or completely lack leaf gaps. Leaf traces are C-shaped, endarch, with one protoxylem strand, and have sclerenchyma lining the adaxial concavity. Leaf bases have stipular wings with large patches of heterogeneous sclerenchyma and a few scattered strands outside of the heterogeneous sclerotic ring. Patches of sclerenchyma occur inside the ring and outside of the vascular tissues. Numerous diarch roots arise singly or doubly from the leaf traces as they depart the axis stele. Although the stem compares fairly closely to both Ashicaulis Tidwell and Millerocaulis Erasmus ex Tidwell emend. Tidwell, it is most similar to Millerocaulis. However, the combination of characters observed in our specimen differs from that of the seven known species of Millerocaulis. This stem is described as Millerocaulis embreei sp. nov. and is the youngest known species of the genus and the first to be found in the Northern Hemisphere.     

A THREE-DIMENSIONAL RECONSTRUCTION OF THE VASCULAR SYSTEM TO THE LODICULES,ANDROECIUM, AND GYNOECIUM OF A FERTILE FLORET OF PANICUM DICHOTOMIFLORUM (GRAMINEAE)

A three-dimensional reconstruction of a fertile floret stele of Panicum dichotomiflorum approaching anthesis was made by a new technique using superimposition of tracings of 80, 1-μm thick serial sections, cleared tracing film, and mounting adhesive. From a collateral bundle, which also served as the median trace to the fertile lemma, most of the vascular tissue branched adaxially and horizontally to become the sole vascular supply to the two lodicules, three stamens, and pistil. The xylem branched at a low level to form a broad and long vessel plexus. The phloem branched at a higher level to overlay the vessel plexus on the right and left with an arc of horizontal sieve tubes in a phloem plexus. Those sieve tubes and vessels which rose after branching from the horizontal plexi assumed a more vertical course in the floret stele. Traces to the right and left lodicules arose from the lower abaxial portions of the flanks of the floret stele. Vessels ascended vertically from the xylem plexus and passed through the phloem plexi and joined with the sieve tubes there to exit at the same level and become the right and left lodicule traces. The vascular tissues to the three filament traces arose from different higher levels of the stele. The sieve tubes for the median filament trace arose vertically from the abaxial side between but above the lodicule traces. At higher levels the sieve tubes for the lateral filaments rose from the horizontal arcs of the flanks of the stele and departed it tangentially. The vessels destined to the filament traces arose in the center of the floret stele from adaxial portions of the horizontal plexus, ascended between the arcs of phloem, exited the stele simultaneously above the phloem of the traces, and followed the courses of their respective sieve tubes. The adaxially displaced apex of the floret stele then contained the vascular tissue related to the pistil. All the sieve tubes and vessels of the floret stele were embedded in a matrix of intermediary cells. The peripheral intermediary cells associated with the vessel plexus were xylem transfer cells with pronounced wall ingrowths. At higher levels in the floret stele, intermediary cells in scattered locations near sieve tubes or vessels had less conspicuous wall ingrowths. No preferred orientation of transfer cells with any particular trace was noted.