Ultrastructure of Phasmid Development in Meloidodera floridensis and M. charis (Heteroderinae)

Phylogenetic characters for Heteroderinae Luc. et al., 1988 are evaluated in Meloidodera which is believed to have primarily ancestral characters. Phasmid ultrastructure is observed in second-stage juveniles (J2), third-stage juvenile males, fourth-stage juvenile males, and fifth-stage males of Meloidodera floridensis and M. charis. Phasmid secretion occurs inside the egg before the J1-J2 molt. Before J2 hatch, concentric lamellar membranes occur within the sheath and socket cells. Some membranes become lamellae of the sheath cell plasma membrane; others become multilamellar bodies. During early molting, plasma membrane lamellae disappear and a distal dendrite segment appears in a rudimentary canal. After the molt, the distal dendrite is not present within the canal. The phylogenetic utility of phasmid features is discussed. In both species the ampulla shape and size between molts are stable features in juveniles and males. The posthatch J2 sheath cell receptor cavity may vary in a species specific manner, but comparative morphology requires precise timing after hatch.     

蛤蚧前背侧室嵴(ADVR)的分区及细胞形态学研究

采用解剖学方法和绀织学方法仔细观察,分析蛤蚧（Gekko gecko）前背侧室嵴（ADVR）的形态学分区,发现以ADVR表面的浅沟为标记,参照细胞着色深浅,细胞密度分布特征以及细胞形态大小,可将ADVR分为内侧区（ma）、嘴外侧区（rla）和尾外侧区（cla）等3个部分,为ADVR的结构功能的深入研究提供了形态学依据。     

Parallel evolution in mammalian and avian brains: comparative cytoarchitectonic and cytochemical analysis

Summary Comparative morphology, which is based on the selection theory of evolution, analyses the impact of function upon structure and, therefore, emphasizes the adaptive events and biological advantage during the evolution of organs. A comparison based on analogies is described here as an adequate method. The hypothesis is proposed that the evolution of the brain follows the same trends in birds as in mammals. This hypothesis is proved by (1) allometric studies of brain weight and brain structure volume in relation to body weight in mammals and birds; (2) architectonic studies using image analysis on cell and fibre stains as well as on histochemical preparations and receptor autoradiography; and (3) hodological studies with injections of [³H]leucin, HRP and WGA-HRP. The results reveal a vast amount of structural and functional similarities in avian and mammalian brain organization, especially an expansion of structures that permit multimodal integration capacity in the telencephalon. Thus, a parallel evolution occurred in these two groups of vertebrates. It is argued that this may be a general phenomenon in evolution. A cladistic approach, which is based on the concept of homologies (plesio-, apomorphies), pushes aside the existence of analogies. For this reason, cladism does not seem to be a method to answer questions of evolutionary morphology adequately.