156 



THE TESTES, BY V. LA VALETTE ST. GEORGE. 



Metschnikow* communicates some important facts respecting 

 the development of the spermatozoa, which unfortunately are 

 inaccessible to me. According to a detailed abstract of his essay, 

 by Hensen and Kupffer, he found sperm cells in the Earth- 

 worm, with granular nuclei. The granules run together in 

 the interior of the nucleus, and form a smooth spheroid, which 

 elongates with the nucleus, whilst the plasma of the cell is pro- 

 truded at one side to form the tail. 



In the River Crawfish the head originates in an independent 

 intercellular formation, that lies beside the nucleus. More- 

 over in Flies the nucleus plays no part ; but the granule-heaps, 

 from which the spermatozoa proceed, divide, and then coalesce 

 again into a single mass. The large zooids of Cyprois 

 develop in a similar manner, near or at the side of the 

 nucleus. 



Balbianif also observed a body near the nucleus of the cell, 

 which developed into the head of the spermatozoon. 



I have continued my researches on the development of the 

 spermatozoa up to a very recent period, and shall now give 



Fig. 183. 



Fig. 183. Development of a spermatozoon in the Guinea-pig, a, 

 head cap. 



briefly my views upon the subject. I have already fully 

 detailed the mode in which the sperm cells multiply. I regard 

 the starting-point for the consideration of the development of 



* Memoires de V Academic de St. Petersbourg, 1868. 



t Journal de V Anatomic et de la Physiologic, 1868, p. 218. 



