虎纹蛙（RANA RUGULOSA）视网膜结构与环境适应性的研究

在光镜和电镜下观察了虎纹蛙（Rana rugulosa)视多膜的组织结构，着重探讨了色素细胞和视细胞的形态结构。视网膜中三个核层及两个网状层分布均匀，无中央凹。色素细胞内含有大量的脂滴、色素颗粒、髓样体和形状各异的溶酶体等。视细胞由视杆细胞和视锥细胞组成，视杆细胞占多数。在视网膜中央区，视杆细胞数与视锥细胞数之比为1：1；在周缘区，两者数量之比为3：1，视杆细胞外段呈高柱状，体积远远大于视锥细胞外段，肌样体内有大量的微管。视锥细胞外段呈矮锥形，椭圆体内有一球状小体。视细胞与节细胞数量之比为3．68：1。结果表明，虎纹蛙视网膜结构特征与其生活于田间、山涧等弱光环境和捕食习性是相适应的。图版1（图1－图10）表2参14

STUDIES ON RETINAL STRUCTURE OF RANA RUGULOSA AND ITS E NVIRONMENTAL ADAPTATION

The retinal structure in Rana rugulosa was studied using light an d electron microscope, and the structure of pigment cells and visual cells was a lso studied. The three nuclear layers and the two plexiform layers are evenly di spersed in the retina. No forea centralis is founded. There are many lipoids, ly sosomes, myeloids and granular melanins in the pigment epithelial cells. There a re rods and cones in the retina, and the rods are predominant. The ratio of rods to cones is about 1:1 in the center, and about 3:1 in the periphery. Outer segm ent of rods is high cylinder, and its volume is bigger than that of cone. There are many microtubes around the myoid of rods. Outer segment of cones is low cone , a globule is localized in each ellipsoid of the cones. Th e ratio of the visual cells to the ganglion cells is about 3.68:1.This study sho wed that the histological structure of retina in R. rugulosa is principally adapted to low intensity of light and hunting for food. Plate 1 (Fig 1 ～10)， Tab 2, Ref 14