1 82 PROTOPLASM 



resting condition of the cell, however, these fibrils are 

 supposed to be connected together in a network, as is 

 also the case with the nuclear framework. 



Finally, the fibrillar structure has found an eloquent 

 defence in a work of Camillo Schneider which has appeared 

 recently (1891). Since the considerations urged by him 

 are especially directed against my conception of proto- 

 plasmic structures, I must examine them rather more in 

 detail. Schneider has investigated partly the same objects 

 as I myself studied, viz. the eggs of sea-urchins and Ascaris, 

 Vorticellce, Triclwplax adhcerens, etc. He finds everywhere 

 in the protoplasm twisted fibrils of the same thickness 

 throughout, without a trace of nodular thickenings ; in fact 

 it even appears to him not impossible that the entire cell 

 may consist of a single enormously twisted filament. The 

 investigations were undertaken with Zeiss jL homogeneous 

 immersion, while I worked, as has been said, with the 

 Apochromatic 2 mm., Ap. 1'30 and 1*40, of Zeiss, and the 

 oculars 12 and 18. Now if Schneider thinks himself in a 

 position to assert (p. 5) that " an alveolar framework or a 

 net-like connection of the filaments is as a matter of fact 

 not present in Strongylocentrotus in the ova investigated," I 

 must for my part reply just as definitely that both are 

 present, and that Schneider gives an entirely false repre- 

 sentation of the microscopic image. I will not appeal to the 

 fact that the great majority of observers, and among them 

 quite a number of the first rank, represent the same opinion 

 as myself with regard to the microscopic appearance, but I 

 prefer to subject the figures given by Schneider to a brief 

 criticism. He remarks (p. 2) with regard to them that 

 those first executed did not represent the framework quite 

 correctly, and refers to the explanation of the figures with 

 regard to this. Here I find it stated only for Fig. 19, 

 " Framework drawn very accurately." The figure represents 

 a section through a spermatogonium of Ascaris. By careful 

 study one will find in this figure quite a number of reticular 

 connections of fibrils, in fact they are even figured as forking. 

 This appears still more strikingly in Fig. 21, of which it 

 is stated that the framework is drawn correctly only in part ; 



