514 Universitij of California Puhlicatioiis in Zoology [Voi,. lid 



Budding 



Instances of budding have been found in C. decumani in material 

 from the mouse, from the rat, and in induced cross-infections from 

 each of these animals to the other. 



One important feature, however, differentiates the budding process 

 in C. decumani from that in C. rnuris. This is the absence of its 

 association with an excessive amount of chromatoidal material or with 

 the general presence of chromophile ridges. A comparison of the 

 figures at the top of plate 48 with those on plate 45 brings out a most 

 striking difference. This feature affords important evidence in favor 

 of the theory that a pore is normallj' present in the cyst wall and that 

 at the proper juncture in the life history, this opens and permits the 

 contents of the cyst to pass to the outside. Figure 54, plate 48, shows 

 a first bud in the early stages of formation. Figure 55 shows a 

 nucleus at the pore or point of emergence of the bud. It is somewhat 

 pointed and ha.s begun to elongate. Three other nuclei remain in the 

 cyst and there are empty patches in the cytoplasm, the material from 

 which ha.s gone to form buds that have previously been discharged. 



Mitosis 



The general process of mitosis is similar to that of ('. nniris, but 

 certain important differences should be noted. 



Prophase. — The first indication of this phase is the enlargement 

 of the halo or gray area around the karyosome (pi. 46, figs. 33, 34) 

 in which chromatin granules, much smaller than the chromosomes, may 

 appear. About this time the large, massed karyosome begins to divide 

 into two parts (fig. 34) which move away from each other. As the 

 portions separate, they are connected by the intradesmose (fig. 38). 

 These two masses take up their position at either end of the somewhat 

 elongated nucleus (pi. 47, fig. 39) and form the centrosomes. As the 

 amount of chromatin material encrusted on the nuclear membrane 

 becomes less during these processes of development, it is probable that 

 a portion of this material functions in the formation and organization 

 of the spindle and chromosomes. In the gray-staining area between 

 the centrosomes, the spindle emerges with the chromosomes arranged 

 on its fibers. As in C. murL<i. no linin fibers are seen in nuclei in the 

 late prophase. 



Metaphase. — Figures of the metaphase (pi. 47, figs. 41, 45) in this 

 species exhibit four chromosomes. They are spheroidal in shape, one 



