RETINA OF RIVER DOLPHIN LIPOTES VEXILLIFER

The structure of retina of the Lipotes Vexillifer has been studied quantitatively under light microscope. The results obtained are as follows.(ⅰ) The thickness of the retina is 268 μm. The lamination of retina can be clearly distinguished. It consists of 10 layers. The thicknesses of the layers from pigment epithelium to internal limiting membrane are 12 μm, 44 μm, 2 μm, 48 μm, 20 μm, 36 μm, 68 μm, 32 μm, 8 μm and 2 μm respectively.(ⅱ) The number of cells in the outer nuclear layer is larger than that in the inner nuclear layer. Two types of cell can be distinguished in this layer. The number of receptors and ganglion cells is in a ratio of 12 to 1. These results show that the retina type of the Lipotes corresponds to that of nocturnal animals.(ⅲ) The diameters of ganglion cells range 1.5—37 μm with two peaks at 6 μm and 35 μm. This means that the ganglion cells fall into two groups according to size, and this has been proved by the observation on morphology of ganglion cells in the wh     

白鱀豚视觉通道的组织学研究——视网膜

本文对白(既鱼)豚视网膜进行了某些定量研究,并观察了其结构.1)视网膜厚度为268μ.2)外核层细胞数约为内核层细胞数的两倍,光感受器与神经本细胞数之比为12:1,这表明白(既鱼)豚视网膜属于夜间动物视网膜类型.3)神经节细胞直径范围为1.5—37μ,在6微米和35微米处有两个高峰.说明按胞体大小神经节细胞可分成两类.在视网膜不同部位,大小神经节细胞的比例变化不大.4)在视网膜上未见中央凹,也未见神经节细胞密度很高的中央区和视条纹。