308 HUMAN PHYSIOLOGY 



solid elements, the spermatozoa. The seminal fluid contains 

 iSfo solids which include chiefly proteids, as also lecithin, 

 cholesterin, fats, salts, and spermin (Diethylen diamine). 



Spermin, having a constitution of C 2 H 4 <(' NH ^>C 2 H 4 , is a 



base and is present in the fluid as the salt of phosphoric acid 

 and by evaporation of the fluid is precipitated as crystals. 

 The spermatozoa contain the ordinary constituents of 

 nucleated cells, i.e. proteid, nucleo-albumin, nuclein, nuclein 

 bases, potassium phosphate. 



The spermatic filaments or spermatozoa are cells with 

 pear- or oval-shaped heads and the attached rod-shaped 

 middle piece which passes over into the threadlike tail. 

 The length of the whole spermatozoon is 0.05 mm. The 

 cells are poor in proteids, the head being the nucleus, and 

 the middle piece and the tail the protoplasm. 



The spermatozoon moves about by the whiplike move- 

 ments of the tail and, during its movements, rotates about 

 its long axis. The movements of the spermatozoon are 

 most lively immediately after the ejection of the seminal 

 fluid. It is favored by weak alkali reaction. Strong alkalies 

 and also acid reactions inhibit the movements. In the 

 genital canals of the female the spermatozoa retain their 

 movements for a very long time. 



2. Formation of the spermatozoa. The formation of the 

 spermatozoa takes place in the convoluted tubules of the 

 testis. Certain cells of the walls of these canals change to 

 the spermatoblasts which grow out into the canal. By cell 

 division and the separation of the newly built cells the 

 spermatoblast forms the spermatozoon. In this the nucleus 

 forms the head, while the protoplasm forms the middle piece 

 and tail. Concerning details of the morphological changes 

 in this process the results of investigators are contradictory. 

 In the testis there is formed simultaneously, in some unknown 

 way, the fluid in which the spermatozoa are suspended. 

 The formation of spermatozoa in the testis takes place, no 

 doubt, continuously. The seminal fluid is passed into the 



