104 PROTOPLASM 



completely structureless and glassy even with the strongest 

 magnifications. The only thing to be observed distinctly 

 in the stronger stems is a fairly thick dark border, appear- 

 ing like a pellicle, and below that a clear margin. The 

 two together remind one strongly of a marginal alveolar 

 layer. With regard to the peculiar nature of the pseudo- 

 podia, their origin from the tuft of protoplasm, with its 

 fibre-like meshed structure, deserves special consideration. 

 I have frequently convinced myself definitely that the 

 structureless protoplasmic mass of the pseudopodia arises 

 quite directly from the fibrous meshed structure of the 

 tuft. The protoplasmic structure of the latter can be 

 seen to become rapidly paler, and to finally completely 

 vanish (Plate II. Fig. 4). The fibrous structure can also 

 be occasionally traced as far as the basal region of the 

 pseudopodia. Hence it seems to me certain that the hyaline 

 protoplasm takes its origin directly from that which is 

 structured. The study of the living Gromia, moreover, 

 furnishes still further proof for this immediate transition 

 between the two kinds of protoplasm. It was occasionally 

 observed that a hyaline pseudopodium was continued 

 distally into a protoplasmic swelling of fibrous meshed 

 structure, which exactly recalled the fibrous tuft at the 

 mouth of the shell, even in the fact that from it a larger 

 number of finer hyaline pseudopodia radiated out. This 

 observation furnishes, on the one hand, a greatly-desired 

 proof for the direct origin of the hyaline pseudopodia 

 from the fibrous protoplasm, while, on the other hand, 

 it proves just as definitely that the hyaline protoplasm 

 can pass again into that which has a fibro-reticular struc- 

 ture, for in no other way can the production of the struc- 

 ture in question, in the course of a pseudopodium, be well 

 explained. 



There are still other observations which point to the 

 transformation which I have just mentioned, of the hyaline 

 protoplasm into that which has a meshed structure. In the 

 fine pseudopodia one occasionally observes at the sides 

 more or less irregular lumps of protoplasm, or even mem- 

 brane-like expansions, which appear distinctly reticulated. 



