An Experimental Study of the Size of the Pupil and Lens during Wolffian Lens Regeneration

Three groups of adult Triturus pyrrhogaster were subjected to unilateral lentectomy (Group A), unilateral lentectomy and amputation of the tail (Group B) and bilateral lentectomy (Group C). These living animals were kept in water at 28°-30°C and the size of the pupil and the regenerated lens were studied from the 12th to 40th post-operative day using binocular microscopes. The results showed that in all stages, except the early stage, the area of the pupil and the projected area of regeneration were highly correlated, and therefore, the growth in size of the regenerated lens was greatly affected by the size of the pupil. However, the above-described experimental procedures had hardly any effect upon the size of the regenerated lens

The Fine Structure of the Pancreatic Endocrine Cells of Salamander, Hinobius nebulosus

The pancreatic endocrine cell of adult salamanders, Hynobius nebulosus, was studied with light and electron microscopy. The following results were obtained. 1. The endocrine cells were distributed individually or in small groups, islets, and were located either in the acinus or in the duct epithelium. 2. Two types of endocrine cell group, the A cell islet and B cell islet, were observed. Each islet was light-microscopically composed of two to five cells, but electron-microscopically, only two or three cells were in direct contact with each other. 3. These islets were not always composed of the same cell type, but frequently were mingled with other cell types. 4. A and B cells were easily distinguished on the basis of the morphology of secretory granules. 5. In the B cells, the secretory granule core did not show a typical crystalline pattern. Crystalloid structures originated from mitochondria were occasionally encountered and intracytoplasmic filaments were most prominent. 6. D cells were identified by the correlative observation of thin sections with an adjacent semithin section stained with silver impregnation by HELLMAN and HELLERSTROM. The D cell secretory granules were electron low dense to moderately dense and showed varying numbers of elongate profiles besides round ones. 7. F-like cells contain electron dense, elliptic secretory granules except for spherical ones. 8. Another type of cells was distinguished. They had a scanty cytoplasm which contained extremely dense, secretory granules with different shapes. 9. The average long and short diameters of secretory granules of each cell type were measured using Reiz-ASM image analyzers