32 HARLEY N. GOULD 



doubt that they persist through the transition period without 

 losing their real differentiation, though the form and staining 

 reaction of some of them are affected by the chemical changes in 

 the gonad. 



The newly formed layer of cytoplasm all around the periphery 

 of the gonad belongs, in all probability, to the follicle cells, al- 

 though the cytoplasm of the germ cells which lie in it is not always 

 distinguishable from the syncytium. It will be recalled that in 

 immature and neuter animals there is also a syncytium around 

 the periphery of the gonad containing follicle nuclei (figs. 1, 2, 

 3, 4, 50); and if regression of the testis takes place in small 

 males, as it may do, the female condition does not immediately 

 ensue, but the gonad returns to the neuter condition pending 

 further growth of the animal. In such cases the gonad assumes 

 the same appearance as in any neuter animal, the germ cells 

 and follicular syncytium being present exactly as in a specimen 

 which has never developed a testis. This has been observed 

 in specimens which were brought into the laboratory as small 

 males and later lost the male condition. 



In the shrunken gonad the cytoplasm of the follicle cells is very 

 loose and vacuolar (figs. 42, 43, 44, 45). The surface presented 

 to the lumen is very irregular. The degenerating cells in the 

 lumen becomes more or less fused into a mass. Even before this 

 happens, however, processes from the peripheral cytoplasm reach 

 out and join them (fig. 42), and the cells finally become enclosed 

 within it (figs. 43, 46). The absorption and solution processes 

 result in a thickening of the cytoplasmic layer. Many granules 

 appear within it, which may be the result of coagulation of the 

 cytoplasm itself, or the remains of the dissolving cells, or both. 

 When all the remaining material in the lumen has been dissolved, 

 typical germ cell nuclei again become evident in the periphery 

 and a concentration of the cytoplasm, or a change in the staining 

 quahty of the cytoplasm, takes place about them (fig. 47). 

 This results in the germ cells becoming more and more clearly 

 distinguishable from the loose cytoplasm of the thick syncytial 

 layer (fig. 48). Part of this thick layer itself seems to dissolve 

 later, leaving faintly staining strands of a loose network, and 



