OTHER /'//; /r\ AS TO ITS NATVKI-. 223 



assume a spherical form, which luul been pointed out by tin- 

 adherents of the theory of its fluid nature. When this phenomenon 

 occurs normally, it was said to depend upon the peculiar organi- 

 sation of the solid particles of the framework; he thus intn. 

 duced a mock explanation in the place of a natural one. 

 For the most part, however, the assumption of the spherical form 

 was to be referred to an abnormal state of the protoplasm, which 

 would hold good for the rounding off which takes place in plas- 

 molysis, the spherical form of drops of protoplasm that have 

 oozed out, and so forth. In these cases the protoplasm is 

 supposed to become usually more watery ; the framework of solid 

 particles of protoplasm breaks up, but may subsequently re- 

 generate itself. Just as little does he allow the spherical form 

 of vacuoles to hold good as a proof, since the formation of 

 vacuoles takes place in the abnormal condition an assertion 

 which betrays a certain amount of inexperience in these matters. 

 It cannot at any rate be asserted that Velten has based his vie\v 

 upon sufficient grounds. 



Hanstein in 1880 and 1883 set forth in still more detail the 

 views he had already expressed in 1870. It appears from them 

 that he had taken up to some extent the opinion already ex- 

 pressed by de Bary with regard to the protoplasm of the Myxo- 

 mycetes. The " fluid " as well as the non-fluid parts of which 

 protoplasm is composed are supposed to be " forms of the same 

 protoplastin, which only differ from one another in the amount 

 of water they contain " (1880, p. 163). The partitions formed 

 by the non-fluid protoplastin, which is deficient in water, within 

 and around that which is fluid, are explained by him as some- 

 times viscid, sometimes solid. The fluid part he termed encJit/lciint 

 (1882), the hyaline ground substance of the entire protoplasm, 

 hyaloplasma, and the granules lodged in it the microsomes. His 

 enchylema is, therefore, in its turn equal to hyaloplasma + micro- 

 somes. There is no need to point out specially that the use, 

 which at a later period was made of the term enchylema, has 

 nothing to do with the original meaning of this term in Hanstein. 



We now turn to the numerous observers who have described 

 filamentous or reticular structures in protoplasm. From the 

 foregoing account we have learnt that theoretical deductions, 

 as well as observations and speculations upon the phenomena 

 of movement, had already necessitated the assumption, and 

 finally the discovery, of such a structure. I think there is no 

 necessity to go through the views of the numerous observers 

 of filamentous or reticular structures in detail, as they have in 

 part been indicated already. It is sufficient to point out 

 that the majority have more or less plainly declared that they 



