246 PROTOPLASM 



peculiarity of protoplasmic structure is also easily and surely 

 explained on the basis of the foam theory, while I am not 

 able to understand how, by means of the theory of a support- 

 ing framework, it could be shown why the granules always 

 take up their position in the nodal points of the framework, 

 and do not appear in the course of its meshes. 



(A) Badiate Appearances in Protoplasm during Cell 

 Division 



For a further and an important point of agreement be- 

 tween artificial foams and protoplasm we refer finally to the 

 radiate appearances which may appear in both, and which 

 can be demonstrated to depend upon the same structural 

 relations, i.e. iipon the more or less pronounced arrangement 

 of the alveoli into consecutive rows in certain directions. 

 As I showed before, the radiate appearances of the artificial 

 foams very probably depend upon diffusion processes in 

 them ; that is to say, the alveoli arrange themselves in series 

 in the direction of the diffusional exchange, and to a certain 

 extent in the direction of the diffusion currents if this 

 expression is permitted. This experience agrees very well 

 with the conclusions at which I arrived many years ago 

 with regard to the significance of radiating phenomena in 

 protoplasm. 



As far back as 1874 I found that round the contractile 

 vacuole of the large Amoeba terricola, during the process 

 of diastole, a very beautiful and fine striation, radiating out 

 on all sides, could be observed in the protoplasm. When I 

 . occupied myself later with the radiate phenomena which, as 

 a rule, make their appearance during cell division at the 

 poles of the nuclear spindle, I concluded, partly on the 

 ground of this earlier experience, partly from the appear- 

 ances in the protoplasm during cell division, that the suns 

 at the poles of the nuclear spindle owe their origin on the 



that granular deposits are contained in the framework, which cannot, on 

 account of their minuteness, he plainly made out, just as, in fact, it is often 

 impossible to decide definitely in tlie case of the visible granules whether 

 they occur singly or whether they are groups of minuter granules. 



