APPARENT RETICULAR STRUCTURES 175 



deposits. Since Carnoy's investigations of 1885 and 1886, 

 upon the cells of numerous Arthropods, and the sexual 

 products of Nematodes, did not make any essential altera- 

 tions in his fundamental conceptions, but rather confirmed 

 them .for these objects in every way, there is no need to 

 go more specially into these later works. 



As has been stated already in the Introduction, in 

 1885-86, when giving a description of the reticular 

 protoplasmic structures of Noctiluca and some Ehizopods, 

 I defended the standpoint I had already taken up in 1878, 

 namely, that we are not dealing with a reticular, but with 

 an alveolar or froth-like structure. 



As far back as 1882 Flemming had expressed the 

 opinion, with regard to the reticular structure described by 

 Klein in certain gland cells (especially the goblet or 

 mucous cells), that the relatively coarse reticular structure 

 of the secretion masses of these cells have in any case nothing 

 to do with the true minute structure of protoplasm. I 

 must declare myself entirely of this opinion. The com- 

 parison of various works which have appeared since upon 

 this subject — such as the investigations of Schiefferdecker 

 (1884), List (1885, 1886), Paulsen (1885, 1886), Zerner 

 (1886) — is altogether in favour of this view. From these 

 results it seems to me beyond doubt, as has been said, that 

 we have to deal here with coarsely vacuolated structures, 

 the origin of which from the finely reticular protoplasm of 

 the original gland cells is still in need of being further 

 cleared up. The descriptions of List especially, make it 

 quite clear that the so-called stalk of the cells still consists 

 of the original finely reticular protoplasm ; the theca also 

 seems to be merely a continuation of the latter. The chief 

 question of which a solution is required may be stated as 

 follows : does the mass of the secretion, with its coarsely 

 reticular structure, arise by direct modification of the original 

 protoplasm, or is it a secreted vacuolar mass ? 



As has been pointed out several times already, it is 

 frequently, in fact as a rule, very difficult to decide, whether 

 the reticular structures described by earlier observers were 

 really the minutest protoplasmic structures, or whether they 



