256 PROTOPLASM 



We have come across, however, a considerable number 

 of fibrous alveolar structures which cannot be brought into 

 direct connection with the streaming phenomena of the 

 protoplasm, but which certainly might depend upon similar 

 causes. Here in the first place stands the fibrous alveolar 

 structure of the axis cylinder, as well as of the elongated 

 connective tissue cells which have been described between 

 the nerve fibres of the ischiadic, the fibrous structure of the 

 cells of the capillaries and of the processes of the ganglion 

 cells, and finally, also the more or less confusedly fibrous 

 nature of the protoplasm of the ganglion cells them- 

 selves. In these cases we are always concerned with proto- 

 plasmic bodies which have grown out very strongly in 

 certain directions, to which the course of the fibres of the 

 meshwork invariably corresponds. We must therefore 

 imagine that we are dealing with a viscid alveolar mesh- 

 work, which is stretched in a definite direction by the 

 growth of the cell. I am able to further support this 

 by the fact that the processes of the very richly 

 branched connective tissue cells, which occur between the 

 longitudinal muscle cells of Lunibricus terrestris, also show 

 the fibrous alveolar structure very beautifully, just like the 

 pseudopodia of Ehizopods. The confused fibrous structure 

 which appears chiefly in greatly branched ganglion cells, 

 probably has its cause in the fact that during the outgrowth 

 of the numerous processes the action of tension is exerted in 

 various directions upon the protoplasm, which is indeed 

 plainly expressed also in the fact that the fibrous structures 

 of the processes always penetrate more or less deeply into 

 the cell, and here combine with one another in the most 

 various ways. On the other hand, however, it is by no 

 means necessary to exclude local tensions set up within the 

 protoplasm of the cell itself, which further complicate the 

 structure. There are many examples of such protoplasm 

 with a confused fibrous structure. I will here only refer to 

 a very good one, namely, the protoplasm of the large 

 medullary sacs of Ascaris lumbricoides and the medullary 

 substance of its muscles generally. 



A question of fundamental importance is raised, however, 



