CHAP, iv.] OF ANIMAL GENERATION. 331 



these fecundating corpuscles, have been called, always by 

 analogy, male embryonary cells. 



In the phanerogamic plants the male ovula are the great cells, 

 which are called pollinical utricles, and the products of their 

 fractionment are pollinical cells, each of which ends by represent- 

 ing a particle of pollen. It is the content of these particles of 

 pollen, or favilla, which is the fecundating substance. The evolu- 

 tion is here less complete than that of the male embryonary cells. 

 In effect, these last resemble at first, almost identically, the 

 pollinical cells. But arrived at a higher degree of maturity, they 

 differenciate themselves more, and their content becomes sper- 

 matozoary, or spermatozoid. If the content of the particles of 

 pollen does not organise itself into corpuscles, endowed with a 

 movement of totality, it is not, nevertheless, completely im- 

 mobile, and the granulations observable therein are animated by 

 movements comparable besides with those which are effected in 

 many other vegetal cells. Whatever, moreover, may be the 

 apparent dissemblance between the favilla of the particle of 

 pollen and the mobile fecundating corpuscle, spermatozoary or 

 spermatozoid, the phenomenon of fecundation does not, on that 

 account, change in its essence. On the whole, the fecundating 

 substance penetrates always into the ovulum, and when once it 

 has arrived there its molecules sever and untimately blend with 

 those of the female ovulum. 



The form of the spermatozoaries and of the spermatozoids is 

 somewhat variable. These fecundating elements are globulous 

 in some vegetals ; they are also globulous in the myriapods and 

 some crustaceans. But in general they are more or less filiform, 

 and at one point swelled out. They have already this form in 

 the male embryonary cells, when, before the rupture of those 

 cells, they are seen to be rolled spirally (Fig. 53). 



As a rule the enlarged part of the spermatozoary is at one of 

 its extremities. This part is of variable form, cylindrical, spheri- 

 cal, oval, elongated to a point, and so on. The spermatozoaries 

 of the mammifers have a somewhat short head and a caudal 



