52 



wards [d'^, s^ in fig. 59) these nuclei divide and fragment 

 and form tiny masses of irregularly-shaped chromatic 

 bodies embedded in a dense matrix of protoplasm. In the 

 hinder third of the testis the cellular layer of its wall 

 gives off numerous branched intra-testicular prolongations 

 [i. y. in fig. 59). These prolongations divide up the 

 substance of the testis into a number of separate masses 

 by means of their branches, which freely anastomose with 

 one another. In this way the cavity of the testis becomes 

 sub-divided into a number of irregular chambers, each of 

 which is filled with a mass of developing spermatozoa. 

 The next stage in the development of the sex cells is seen 

 where the chromatin bodies retreat towards the periphery 

 of the masses of protoplasm in which they are distributed 

 {cl?, 5-), and eventually become congregated together over 

 a very limited area of the latter. Traced a little further 

 back, the chromatin bodies gradually elongate to form the 

 heads of the spermatozoa, and from them are seen to 

 extend delicate filaments, and each mass becomes easily 

 recognisable as being a bunch of spermatozoa {s. -p.). 

 During the last stage in development the intra-testicular 

 prolongations, which have served to nourish the developing 

 sperms, are seen to break down and ultimately liquefy, 

 and the posterior end of the testis becomes filled with 

 spermatozoa floating in a thickish fluid. 



The process of spermatogenesis has also been studied 

 in Anurida by Fernald, but the above account differs 

 very considerably from the description detailed by that 

 author. According to his observations, it would seem 

 that the process is a much more lengthy one than that 

 just described. What are in the present account 

 interpreted as bundles of fully-developed spermatozoa, 

 correspond with his stage where there are a number of 

 elongate granules with fine threads passing from them 



