THE COMPARATIVE MORPHOLOGY OF THE CANELLACEAE. IV. FLORAL MORPHOLOGY AND CONCLUSIONS

The morphology and anatomy of 105 flowers representing 13 species and 6 genera of the Canellaceae are summarized. The flowers are borne in axillary or terminal racemes, cymes, or small groups, or solitary, in an axillary or terminal position. The flowers are characterized as follows: bisexual, hypogynous; sepals 3, thick and leathery; petals, 5–12, free or united into tube at base, rather thick, in 1 or 2 whorls and/or spirals; androecium of 6–12 stamens united by their filaments forming a tube, anthers with longitudinal extrorse dehiscence; gynoecium of 2–6 carpels fused by their ventral margins; 2–6 placentae. There are 2 vascular bundles (rarely 3) to each sepal, 3 to each petal (some of the inner petals have only 1), 1 to each stamen and 1 trace to each carpel. The petal and stamen bundles have a common origin. All the data accumulated in this series on the Canellaceae indicate that the correct systematic placement of the Canellaceae is in the woody Ranales, perhaps in a complex with the Myristicaceae.     

MORPHOLOGY OF MARSILEA VESTITA. I. ONTOGENY AND MORPHOLOGY OF THE SUBMERGED AND LAND FORMS OF THE JUVENILE LEAVES

During their ontogeny, the primordia of the juvenile leaves of Marsilea plants in sterile culture develop 1, 2 or 4 marginal meristems, and these, in turn, contribute cells to the young leaf by anti- and periclinal cell divisions. The final leaves are unifid, bifid, or quadrifid, depending on how many marginal meristems develop, and this is determined early in the ontogeny of the leaf. The mechanism which determines whether or not a marginal meristem develops may fluctuate, as shown by the existence of trifid leaves. Two forms of juvenile leaves are produced, those in a liquid medium, which in many respects resemble the adult quadrifid submerged leaves, and those on a solid medium, which in many respects resemble the adult land leaves.     

蜀龙头骨及脑颅的解剖

本文对蜥脚类蜀龙(Shunosaurus)的脑颅分别从其头骨特征、脑垂体、耳区、视觉系统、脑神经等诸方面进行了较为详细的解剖研究,结果表明 Shunosaurus 内颈动脉不分叉;基蝶骨突强烈收缩;外淋巴囊出现在中耳及 IX、X、XI 孔与颈静脉孔内分外合等现象十分独特.因此,Shunosaurus 应视为一种特化的原始蜥脚类.     

COMPARATIVE MORPHOLOGY OF THE COCHLOSPERMACEAE. II. ANATOMY OF THE YOUNG VEGETATIVE SHOOT

The generic scope and systematic position of the Cochlospermaceae were evaluated using observations from the anatomy of the stem, node, and leaf. There are few basic differences in vegetative anatomy between Amoreuxia and Cochlospermum. Secretory cells and canals, dilated phloem rays, and banded phloem are unifying features. Mature nodal anatomy is 3-trace, trilacunar, and the leaves of both genera have elongate, unicellular, branched idioblasts in the spongy mesophyll. Bixa has some features in common with Amoreuxia and Cochlospermum but is distinctive in vascularization of the petiole, leaf anatomy, and vestiture. Rhopalocarpus is quite different from the above genera, and its placement in a separate family is justified on anatomical grounds. The Cochlospermaceae, consisting of Amoreuxia and Cochlospermum, seem more closely related to the Sterculiaceae and Tiliaceae than to the Flacourtiaceae, Cistaceae, or Violaceae.