40 SPERMATIC PARTICLES. 



which splits up into the spermatic bodies. There are several facts which ought here to 

 be considered before this view is admitted. One is, that the number of bodies composing 

 the fasciculus appears to be in a pretty close ratio with the number of preexisting cells 

 the vesicle would contain ; so that there appears to be a morphological connection, 

 indicating that the structure of the cells as such does not become lost in a granular 

 mass. This may be clearly seen in many of the Passerine birds. Again, it is difficult 

 to conceive how a granular mass can split up into a group of bodies which have not 

 a trace of a granular structure, at least as far as we can perceive, and especially so when 

 many of these bodies have in their interior the remains of an old nucleus, the relics of 

 the former cells. Lastly, it is quite common to perceive in the testicular tubes of birds 

 fasciculi of these bodies of a size so large as shows that it could not have been at- 

 tained within the parent vesicles, but is rather the result of an accidental coincidence, 

 they having a strong tendency whenever they come together to unite in a regularly 

 formed manner; and large groups are continually gathering as they pass along, and not 

 broken up until forced through the vasa deferentia. This point will again come up for 

 consideration in the general remarks upon the modes of genesis. (Vid. Fig. 22-28.) 



4th. Mammalia. — The spermatic particles of this class have a uniformity as to form 

 and shape, and a delicacy of structure, exceeding any other class. They are characterized 

 by a broad, disk-like, neatly sculptured anterior extremity, to which is appended a tail, 

 generally of considerable length. Among the higher orders, there is a remarkable simi- 

 larity, which meets with a considerable modification in those of less rank. Both Wagner 

 and Kolliker have illustrated these forms by many figures. My own observations have 

 been made as to their genesis upon the orders Bimaiia, Caniivora, Rodentia, and 

 Rnminantia. With the exception of a kw important points, the same mode of pro- 

 cedure is observed as in the former classes. Sperm-cells appear, their nucleus is divided, 

 and so on as in the former classes. The spermatic particles, however they may be 

 formed, are more often found, especially in the higher Mammalia, in a free, unconnected 

 state in the parent cell, rather than in fasciculi. In many species of the genus Miis, 

 where the large size of these bodies allows them to be easily seen, I have sometimes 

 perceived them in small fasciculi in the parent vesicle, and have often particularly noticed 

 the fact of these fasciculi being made up of an even number of bodies, and this number 

 corresponding to the results of segmentation, 2, 4, 8, 16, &c., thus making it exceed- 

 ingly probable that these particles are not formed from a granular mass, but rather di- 

 rectly /rom or in the segmented cells. (Vid. Fig. 29-35.) There are some pecu- 

 liarities of these bodies among some of the Mammalia, that deserve our notice. 



Among the Sciuridtx the cephalic portion of the spermatic particle has its largest 



