STUDIES IN THE EXPERIMENTAL ANALYSIS OF SEX. 231 



was not clearly made out, and it was my chief object this 

 year to obtJiin some idea of how this process takes place, to 

 observe, for example, wliether phagocytosis takes any active 

 part in it. 



The condition of arrested growth without any signs of 

 active degeneration is well exemplified by the testis and 

 vesicula seminnlis figured on PI. 14, fig. 10, which was dis- 

 sected out of the perfectly modified male whose appendages 

 are represented in figs. 3 and 4. In PI. 14, figs. 8 and 9, are 

 drawn, on the same scale, the vesicula seminalis and a small 

 portion of the coiled testis of an uninfected male of the same 

 size, showing that the gonad of the infected individual has 

 remained very small and undeveloped. Spermatozoa were 

 entirely absent from the infected individual, whereas the 

 vesicula of the normal individual was crowded with them. 

 There is, however, another point to be observed. Investing 

 the gonad of the normal individual is a thin sheath of con- 

 nective tissue with flattened, darkly staining nuclei (c.s., PI. 14, 

 fig. 9). In the infected individual this sheath is seen to be of 

 proportionately greater thickness. 



In PI. 14, fig. 11, is shown a portion of the testis of an 

 infected male in which the process of absorption of the gonad 

 has proceeded to a considerable extent. In three places small 

 disconnected masses of testicular cells [t.) are seen lying 

 ensheathed by connective tissue ; between the disconnected 

 pieces of germinal tissue nothing remains but the connective- 

 tissue sheath. By staining such preparations with a triacid 

 stain, e.g. Ehrlich-Biondi, small globules are seen lying 

 between the germinal nuclei and the sheath, which take up 

 the orange stain. These globules may be looked upon as 

 degeneration products of the germinal tissue in process of 

 absorption. In none of the preparations which I have made 

 of degenerating gonads is there any sign of phagocytosis, the 

 degeneration appearing to take place by some process of 

 auto-digestion. 



Tui-ning to the degeneration of the ovary, PI. 14, figs. 12 

 and 13, we find exactly the same process. Fig. 12 represents 



