THE SPERMATOGENESIS OF DOMESTIC MAMMALS. 389 
also becomes indistinguishable. The behavior and the form of this chromo- 
some (accessory) during the anaphase and the telophase of the first division 
are quite similar to those of the accessory chromosome of the horse. From 
what is stated above it is obvious that one half of the daughter cells thus 
formed contains the accessory, while the other half does not. 
In the second reduction division, as stated above, the accessory chromo- 
some can be seen in one half of the metaphase plates and is divided at the 
same time with the ordinary chromosomes. It can be recognized till the 
telophase of the second division, and thus we can distinguish two kinds of 
cells, namely, approximately one half of the cells contains sixteen chromosomes 
and the other half seventeen (sixteen ordinary and one accessory chromosome) 
(Figs. 79—82). 
The resting stage of the secondary spermatocyte:—As in the case of. the 
horse, the resting stage of the secondary spermatocyte is rarely found in 
cattle (Fig. 60). 
The nuclei of the resting secondary spermatocytes usually contain several 
chromatin masses (Karyosomes) (Figs. 60, 73, 74). The difference in their 
size is very small, no special large chromatin nucleolus like that which we 
find in one half of the nuclei of the same stage in the horse can here be 
found. The dimorphism of the cells oceurring in this stage of the horse can 
also not be recognized in cattle (Fig. 60). Both the idiozome and the 
mitochondrial granules are found in this stage, a large portion of the latter 
being placed near the former (Figs. 73, 74). 
The cytoplasmic structure »— During the reduction division the mitochondria 
lie outside the spindle (Fig. 66). When the cell is divided into two, they 
seem to be equally distributed in the cytoplasm of the daughter cells (Fig. 71). 
A small spheric body stained faintly with iron-haematoxylin sometimes, 
though rarely, appears in the cytoplasm of the cells in the reduction divisions, 
situated close to the cell membrane (Figs. 65, 75). It is difficult to determine 
whether this body corresponds to the chromatoid corpuscle of the horse or 
not, for in succeeding stages this body is not to be found. It can not be 
compared with the chromatoid corpuscles of the horse, where they first make 
their appearance during the growth stage and are always found in all the 
following stages till the development of the spermatozoa. From its, behavior 
