"NONSENSE" ORIENTATION AS A POPULATION VARIANT

Using 2,570 Mallard, the "nonsense" orientations of two largely separate stocks are compared. Slimbridge birds head off predominately northwestwards throughout the season. Birds caught at Peakirk showed a similar orientation during the early autumn, but during the winter scattered virtually at random, yet without behaving as if disorientated.
A sample of 188 Mallard from London orientated in southerly directions both in autumn and spring, yet could not be responsible for the change at Peakirk because they would not disperse so far. 180 young Mallard from Slimbridge and London stocks were reared in large aviaries. Their first flights were too abbreviated for conclusive results but differences between the stocks were indicated and it is possible that "nonsense" orientations are not learned responses to the local topography.
Ringing recoveries show that the timing of the arrival of immigrants from the Continent coincides with changes in orientation at Peakirk and that their distribution is such that it could explain the different results at Slimbridge. Preliminary releases of Swedish-caught Mallard strongly support the argument.
The implications for the study of bird navigation are briefly discussed.     

THE SENSE ORGANS OF BIRDS

The eyes and ears of birds are compared with those of man so far as the existing state of knowledge allows, and an attempt is made to correlate resemblances and differences with the evolutionary history and the functional requirements of the present day. It is shown that the characteristic shape of the central fovea of the bird's retina cannot be accounted for by supposing that it increases acuity; it is more likely a device for emphasizing angular movements. A brief account of Menner's theory of the pecten is given.
In default of any satisfactory physiological data, an attempt is made to assess the indirect evidence relating to the frequency range and discriminative power of a bird's ear. The conditions for the unambiguous determination of the direction of a sound source are discussed and it is suggested that the asymmetry of the ears of owls is correlated with an enhanced directional sensitivity which, in turn, is related to the dependence of owls on hearing rather than sight in their hunting.
Reference is made to the senses of smell and touch in birds. And there is a brief discussion of the problems of "time" and "direction" senses.     

THE CRUCIFORM MUSCLE AND ITS ASSOCIATED SENSE ORGAN IN SCROBICULARIA PLANA (DA COSTA)

Long dendritic processes from neurones of the sense organ ganglionpenetrate the epithelial lining of the narrow and short ductsituated between the intramuscular slit and a large posteriorcavity which opens to the siphonal space through a narrow canalin the sense organ papilla. Motor nerve fibres innervate theanterior ends of the cruciform muscle strands. The latter becomesstretched during opening of animal and contracted during closure.The slit is widened during opening and narrowed during closure.The sense organ responds to foul water suggesting that it isa chemoreceptor for this stimulus. (Received 10 July 1977;     

中国角蟾亚科精子形态比较及分类学讨论(两栖纲：锄足蟾科)

应用光镜和电镜对角蟾亚科短腿蟾属,拟角蟾属和角蟾属3属18种精子的形态结构进行观察和比较。并通过计算机对其各部位长度进行了测量和计算,结果表明角蟾亚科精子的共同特征是：精子主要由头和尾两部分组成,头部呈螺旋状,尾部为波状或弯曲状,但精子的量度和头部形状在属间和种间存在明显差别,角蟾亚科的精子可分为3类,该亚科精子形态的差异与成体形态学研究结果基本相吻合,精子形态的差异可为该亚科属,种的划分,亲缘关系研究提供新依据。     

THE FINE STRUCTURE OF THE CTENIDIAL SENSE ORGANS (BURSICLES) OF VETIGASTROPODA (ZEUGOBRANCHIA, TROCHOIDEA) AND THEIR FUNCTIONAL AND PHYLOGENETIC SIGNIFICANCE

The fine-structure of the bursicles of members of all threesubgroups of Vetigastropoda (Fissurelloidea, Pleurotomarioidea,Trochoidea) is described. Specific sensory elements (paddlecilia) suggest a chemo-sensory function of the sense organs.This agrees with earlier physiological results which demonstratedthe role of bursicles in detecting predatory sea-stars. Similarpockets in the (secondary) gill-leaflets of the Pseudococculinidae,are not homologous with the bursicles. The lack of bursiclesin group-B hot-vent limpets and in Neomphalus excludes thesegroups from the Vetigastropoda. The bursicles are regarded asa synapomorphic character of the vetigastropod groups provingtheir evolutionary unity. (Received 13 June 1986;     

两种小菜蛾寄生蜂产卵器感器的形态和超微结构

半闭弯尾姬蜂和菜蛾盘绒茧蜂是两种重要的小菜蛾寄生蜂.采用扫描电镜对该两种寄生蜂雌蜂产卵器上的感受器的形态和超微结构进行了观察和研究,结果显示半闭弯尾姬蜂和菜蛾盘绒茧蜂的产卵器形态结构基本相同,都是由两个独立的腹产卵瓣和两个愈合在一起的背产卵瓣包围形成产卵道,与其它种类的寄生蜂相似.借背产卵瓣上的脊与腹产卵瓣的沟连锁在一起,腹产卵瓣可以沿背产卵瓣上的脊前后相对滑动.在半闭弯尾姬蜂产卵器上观察到1种钟形感器、2种腔锥感器、浅凹状感器和分泌毛孔.在菜蛾盘绒茧蜂产卵器上同样观察到了这几种感器,但菜蛾盘绒茧蜂产卵器端部的钟形感器突起较狭长,顶部开有气孔.此外菜蛾盘绒茧蜂产卵器上还存在第3种腔锥感器,其中央突起较低而长,表面有网孔.对各种感受器的形态和分布进行了描述,并对其功能进行了探讨,认为半闭弯尾姬蜂的产卵器较细长,且刺突部位有6个倒钩状突起,背、腹产卵瓣上分布更多的感受器,显示出更强的寄主搜寻定位和产卵寄生能力.