CtAmetogenesis of saccocirrus 31 



Strongyloentrotus eggs in a ' nuclease ' procured from spleen 

 and pancreas, succeeded in dissolving away Schaxel's granules, 

 which did not appear when the eggs were subsequently treated 

 by methods which fixed and stained the granules in eggs 

 not treated by the enzyme solution. 



This work has been especially referred to by some recent 

 writers, who consider that weight should be attached to 

 Miss van Herwerden's statements. 



With certain precautions, which were incomplete, she 

 prepared a proteolytic enzyme from spleen, according to the 

 directions of Sachs (52). Now I submit that her enzyme 

 solution was probably a mixture of several enzymes, ' nuclease ' 

 possibly, but also lipolytic enzyme as well. The fact that 

 cell granules disappear under treatment by such a solution 

 proves nothing with reference to their precise chemical nature. 

 These granules were possibly mitochondria whose proteid 

 basis was washed away by some protease, which would cause 

 them to disappear as definite granules — or what is more 

 hkely. Miss van Herwerden's ' nuclease ' contained a hpoclastic 

 body which swept away the linin content of the mitochondria. 



Until an expert on enzymes prepares solutions whose con- 

 tents are known and whose reactions towards various organic 

 materials are completely worked out in vitro, until the 

 microchemistry and origin of bodies in question are better 

 understood, then and then only should one place any weight on 

 such work by enzyme action as that of Miss van Herwerden on 

 Schaxel's 'chromatin' granules. It should be noted carefully 

 that Schaxel's granules do not produce bodies resembling 

 nuclei, as happens in Apanteles, &c. ; one should not without 

 good reasons call any haematinophilous body chromatin : 

 even if his granules are extruded from the nucleus, they might 

 just as well be nucleolar as chromatinic; and he might with 

 advantage try other methods. 



Zoologists should note carefully that an espousal of Schaxel's 

 views seems to necessitate either the further adoption of 

 a binuclearity hypothesis or the rejection of the chromo- 

 some theory. 



