36 CALIFORNIA ACADEMY OF SCIENCES. [3D See., 



blood, and nearly every one of them possessed this same 

 refractive globule at one side in its granosphere, seldom in 

 the center. In the batrachian plasmocyte the somosphere 

 lies outside on the surface of these globules, never in them. 



The fact that these globules are not always present, nor 

 consistent as regards form, size, and number, induces me 

 to consider them as food particles which are being digested 

 by the somosphere and which may have been either de- 

 rived directly from the blood serum or secreted by the 

 granosphere. In consistency these globules are quite 

 dense, as may be judged from the appearance of the somo- 

 sphere. 



The somosphere would then stand in the same relation 

 to the centrosome as that of the granosphere to the centro- 

 sphere and interior spheres. In other words it constitutes 

 a digestive layer for the nourishment of the centrosomes. 

 It is only reasonable to suppose that such delicate organisms 

 as the centrosomes must have specially prepared nutriment, 

 and that they are unable to directly assimilate food sup- 

 plied by the blood serum and by the granosphere. The 

 process would then be as follows : The nutriment supplied 

 by the blood serum is digested by the granosphere; part of 

 what results from this feeds the various spheres of the plas- 

 mocyte, especially the centrosphere; and as this nutriment 

 is too coarse for the centrosomes, it must, in order to be 

 assimilated by them, be further manipulated by the somo- 

 sphere. 



Unequal Staining- of the Archosomal Spheres. — A point 

 of considerable interest is the unequal susceptibility to 

 stains exhibited by separate archosomes. For instance, 

 in plasmocytes which contain two or more archosomes 

 with a granosphere surrounding each, we often find that 

 one granosphere or centrosphere has accepted a very dark 

 stain while the other remains quite pale. Thus in fig. 65 

 we see that the centrosphere of the upper microcentrum 

 is dark violet, while the lower and larger one is light 

 blue. A similar difference is also seen in figs. 64 and 69. 

 This unequal staining is frequently accompanied by a dif- 



