SPERMATIC PARTICLES. 41 



and finest development, it being a thin and quite transparent disk-like body, as though 

 from the flattening of a cell, the two membranes coming in contact ; and in it may be 

 often seen granules of considerable size, which go to support the view of its cell-mem- 

 brane origin ; these disks, generally circular, have often a slightly pyriform shape, and 

 are of a size equalling one twenty-five-hundredth or one three-thousandth of an inch in 

 diameter. To these is appended a rather long and delicate tail. When making obser- 

 vations on these animals, one must be struck with the similitude of these disk-like 

 bodies to the segmented cells floating beside them in the field. 



Among the Muridce, we meet with a marked peculiarity of form, such as is not met 

 with elsewhere. It consists in a curved, sickle-shaped body, to which is appended a very 

 long tail. This sharp, knife-like portion of the body is situated on one side, so that the 

 spermatic particle has a rather symmetrical aspect. It is difficult to understand how 

 they are formed in this manner, and more particularly so if we attempt to trace them 

 to a cell-origin. The genesis of these bodies in man does not differ at all from that of 

 the higher brute Mammalia. Their form and general characters are too well known to 

 need mention, and I have seen nothing particularly distinguishing them from those of 

 some of the Solipedes and Ruminantia. 



The figures of Buflbn * and Pouchet f savor so much of the fanciful, and offend 

 so much our best notions of the most minute morphological changes, that I shall not 

 allude to them here. And here I may as well say, that most of the spermatic 

 particles of the Mammalia are of such character as to admit of being studied onlv as 

 a whole. And even admitting the very absurd view that they are animals, I should 

 hesitate long before I believed that any one had ever seen their internal structure. 



I have thus rather hastily described the mode of genesis of the spermatic particles 

 in the four grand classes of the vertebrated animals ; a fuller detail would have been 

 inappropriate, as illustrating the grand formula of their genetic morphology, which we 

 have seen is always present. 



I shall now turn to some considerations upon the alleged various modes of their 

 production, after the vitalization by segmentation has taken place, especially as they bear 

 upon the formula just stated, and the commonly received embryological changes of the 

 ovum after segmentation. 



Kolliker % has spoken of five types by which they are developed, viz. : — 



• 



Op. citat. t Op. cital. 



X Beitrcige zur Ke7intniss der Geschlechts-Verhdhnisse, etc. Berlin, 1841. 



