CHAP, i The Cell 



171 



reticular appearances with the older fluid theory. He held 

 that the coarser fibrillar appearances are trabeculae of 

 protoplasm of great fineness, while the local reticular 

 structures of which Fromman spoke are only precipitates 

 separating out in certain places. He based his view largely 

 on the fact that he obtained similar appearances of reticu- 

 lated structure in coagulated drops of white of egg. His 

 view was, broadly, that there are no preformed networks 

 or frameworks, but that certain parts of the protoplasm 

 may under particular conditions become modified to take 

 the form of filaments and strands. 



The fluid theory received substantial support in 1890 

 from Pfeffer. He regarded as viscous fluids the streaming 

 protoplasm of the Myxomycetes, and the principal mass 

 of the ordinary protoplasm of vegetable cells, and while 

 he admitted that the cortical layer of the plasmodium 

 possesses a greater degree of cohesion than the inner sub- 

 stance, and that the outer layer of most protoplasts is to 

 be regarded as more or less solid, he denied entirely the 

 existence of a firm, continuous, and permanently rigid 

 framework. 



Another hypothesis was advanced in the early eighties, 

 which for a time met with some support. It was based 

 upon the granular character which protoplasm exhibits, 

 the granules assuming a greater prominence than in the 

 theories already alluded to. The granules were explained, 

 as we have seen, by the supposition that they represented 

 the nodular points of the reticulum, or the crossing of the 

 fibrils. Hanstein in 1882 considered them to be distinct 

 structures and called them microsomata. In the same year 

 Martin suggested that the fibrillar or network appearances 

 are due to a special arrangement of these granules. Pfitzner 

 held in 1883 that they are viscid or semi-solid structures 

 floating in a fluid ground substance. He accounted for 

 the appearance of filaments by suggesting an attraction 



