No. 3.] EGG OF ALLOLOBOPHORA FCETIDA. 529 



In a fifth preparation nothing was left of the photographed 

 cell after thirty-five minutes in the digestion fluid. We have 

 frequently repeated the above method, with the following 

 results : As a rule, the cell membrane is the first to disap- 

 pear, then the nuclear membrane with part of the cytoplasm, 

 and the contents of the nuclei, with the exception of the 

 nucleolus. In many eggs the large nucleolus is all that is 

 left to mark the presence of the germinal vesicle. 



The yolk-nucleus and nucleoli appear to be the last to 

 succumb to the action of the digestion fluid, but whether 

 this power of resistance is due to their chemical constitu- 

 tion or merely to their relative density we cannot say.^ 



TJie Specific Nature of Archoplas7n. — The specific nature 

 of archoplasm claimed by Boveri has been subjected to 

 repeated attacks. In some cases, however, these attacks 

 lose their force, for the author figures a substance in the 

 cell which morphologically resembles archoplasm and which 

 he dignifies with a special name. A few authors stoutly 

 maintain the specific nature of archoplasm, a few retain the 

 term "archoplasm," but avoid defining it; while the expres- 

 sions of others on the subject are so contradictory that they 

 create a problem as obscure as the one under discussion. 

 This substance, which appears to be fluid in the living egg 

 (Foot (9), pp. 7, 8) and granular after fixation, is in such inti- 

 mate combination, after certain fixatives, with the substance 

 which forms the network, that one is led to question the 

 individuality of the two substances. We are convinced, how- 

 ever, that in this egg the individuality of each substance can 

 be demonstrated, though in many cases the granular archo- 

 plasm is so massed that the cytoplasmic network is completely 

 obscured. Our preparations (Photos 51-53, PI. XLIII) show 



1 These results are quite opposed to Crampton's (6). He finds that the 

 nucleolus " is partially dissolved by artificial digestion," p. 39, and that the yolk- 

 matrix (yolk-nucleus) disappears by digestion, while the cytoplasm remains 

 intact. " With the other stains confirmatory results were obtained, all agreeing 

 in demonstrating the more or less complete removal of the albuminous yolk- 

 matrix and nuclear granules, according to the length of time the section was 

 digested, and showing furthermore the indigestibility of the cell body," p. 39. 

 Crampton's preparations were digested "from one to two hours." 



