So EISEN. [Vol. XVII. 



of the two spheres, we find that under the most favorable con- 

 ditions these fibers also can be resolved into continuous rows 

 of cytoplasmic granules. 



These fibers frequently merge gradually into an alveolar or 

 foam structure, and in many cells such a foam structure is a 

 general one in the spheres (Figs. lo, 14, etc.). But even in this 

 foam structure we have no difficulty in perceiving that the 

 walls of the alveoli contain granules. 



When turning our attention to the two spheres we meet also 

 in them the alveolar structure with granules found elsewhere. 

 This is especially the case in the granosphere, as in it the gran- 

 ules are more densely stainable than in the plasmosphere. The 

 foam structure in the spheres is seen thus to contain granules 

 of uniform size, though here and there some of these granules 

 have joined to form larger composite ones. 



The foam-like structure of spheres is, according to my opinion, 

 due to secretions from the individual granules. If we sup- 

 pose that such secretions are given out by a large number of 

 granules at the same time, and if we also presume that the 

 individual granules possess the power to adhere to each other, 

 the result will, I think, be a foam structure. The summary of 

 the above observations would then be this. Protoplasmic fibers 

 as well as foams are not the ultimate visible arrangement of the 

 protoplasm. All such fibers and foams in the Batrachoseps 

 testes can be further resolved into granules of uniform size, 

 which granules adhere to each other, forming granulated fibers 

 and foams. The fibers and foams are thus only secondary 

 structures and do not represent the ultimate visible structure 

 of the protoplasm. 



If we extend this theory to the spindle fibers we find that all 

 observations go to confirm its correctness. The individual 

 spindle fibers are not only plainly composed of granules, but 

 these granules are often of different sizes and colors, indicating 

 that foreign granules have been taken up and suspended in the 

 thread of the fiber. That the formation of the spindle fibers is 

 really only a readjustment of the previous structure of the 

 cytoplasm is almost certain, but this readjustment cannot be 

 simply the result of a contraction and a drawing out of the 



