S TRA SSB URGER KLEIN 1 67 



from preparations. Since the width of the meshes described 

 is on the whole rather great (0'0027 mm. in the figure 

 provided with a scale of measurement), and the contents of 

 the meshes themselves are drawn as being finely punctate, 

 it seems rather doubtful if the true protoplasmic structure 

 was seen. 



Doubts may also be raised with respect to the net-like 

 structures described by Strassburger (187G) in the proto- 

 plasm of vegetable cells. Both in his treatise on protoplasm 

 and in the second edition of his book on cell formation and 

 cell division, it is almost exclusively the coarser vacuolated 

 structures which are described as reticular. This follows 

 with tolerable certainty from the size of the meshes, the 

 width of which varies, as a rule, from 0'005 to O'Ol 

 mm., though occasionally sinking to 0*0015 mm. The 

 fact, therefore, of Strassburger having occasionally seen 

 the true meshwork of the protoplasmic structure, is cer- 

 tainly by no means excluded. But one thing appears 

 especially noteworthy, namely, that he especially remarks 

 (Zcltt>ildung,p. 217) that the net-like structure of the proto- 

 plasm is in reality a ''dividing up of the protoplasm into 

 chambers, in which the cavities of the chambers are filled 

 by a more or less concentrated solution of albumen." The 

 distinction which he seeks to draw in his treatise on proto- 

 plasm between vacuoles and chambers in the granular proto- 

 plasm is not quite clear to me. Vacuoles are said to be 

 drops of a watery fluid in the protoplasm, but the chambers, 

 on the other hand, are formed by the protoplasm filling up 

 the cell fluid in the form of thin plates connected like a 

 network. This conception of the reticular structure seems 

 to me the more remarkable from the fact that Strassburger 

 gave it up soon afterwards, and in its place adopted the idea 

 of a net-like or spongy structure. 



As we have seen that Schwalbe had already tried to refer 

 the peculiar structural relations of the ganglion cells to their 

 reticular nature, it is especially interesting to note that Eimer 

 in 1877 brought the longitudinal striation of the ciliated 

 cells of various objects into connection with the special 

 arrangement of the usual reticular meshwork. That is to 



o 



