43 2 DEVELOPMENT OF SPERMATOZOA. [sect. 197. 



mingled : on the other hand, in the upper part of the epididymis, and 

 in the testicle itself other elements preponderate, and at last, as we 

 trace the semen to the place of its secretion, these cysts and cells 

 come to form its sole constituents. The sperm-cells and cysts, as I call 

 them, have a certain relation to the spermatozoa, and, indeed, as I 

 have demonstrated recently, they actually give origin to them ; one 

 spermatozoon develops itself from each of their nuclei, the'nucleus 

 becoming elongated, and sending out a thread from one extremity. 

 The proper seat of this development is in the testicle itself, so that, 

 in the normal condition of the organ, we may be certain of find- 

 ing in its internal parts developed spermatozoa in their mother- 

 cells; and these may often be seen in all the seminal tubules 

 without exception. In the normal course of development, the 

 spermatozoa do not become free in the testicle itself, or do so only 

 in very small numbers ; hence, the seminal tubules are far from 

 being the place in which to seek the spermatozoa (although, even 

 here, they will never be missed when water is added, because, by 

 this reagent, the enclosing parts are ruptured). The spermatozoa 

 should rather be sought in the rete testis and coni vasculosi, for 

 here it is that the sperm-cells burst. The spermatic filaments, 

 while included in the cell, have a regular arrangement into 

 bundles, which are curved, so that the heads and the tails of the 

 filaments come together. This is seen when there are many (10 

 to 20) filaments in a cell; when they are present in smaller num- 

 bers, they lie across each other without any regularity. At last, 

 by the rupture of the including cells and cysts, the spermatozoa 

 become free, and entirely fill the epididymis in dense swarms ; 

 here they are found isolated or in bundles, the latter, however, 

 speedily breaking up into their components. In the lower part 

 of the epididymis the whole process of development is, as a rule, 

 completed ; still it not unfrequently happens, that a few interme- 

 diate forms receive a further development, and arrive at their 

 complete formation only when they reach the spermatic duct. It 

 is also worthy of note, that the spermatic filaments, when they 

 are contained singly in separate cells, frequently give to the cell 

 a peculiar pyriform outline (fig. 181, g), and often simply break 

 through the side of the cell, so that a larger or smaller fragment 

 of the cell remains behind in the form of a ragged cap on the head 

 of the spermatozoon, or of a round appendage on its tail : we may 

 often see the great majority of the spermatozoa in the epididymis 

 provided with such appendages on their tails, and these may be 

 recognised even in the matured semen. — For further details on 



