OoO r. CIJFFOKD JKDBELL. 



that chromatin granules are scattered through all the walls 

 of the chambers, whereas I believe that — in C. veneris — the 

 granules are confined to the circumference of each transverse 

 disc-like partition. Schellack thus regards a Cristispira as 

 containing a nucleus of a kind of chromidial form.^ 



Gross's (1910) intei'pretation is peculiar. Although he 

 appears to have observed the same structures as Schellack 

 and myself, he comes to the conclusion that the protoplasm 

 is really structureless, and there is no nucleus of any sort 

 present. The chambers are artifacts, because they can be 

 seen neither in the living organisms nor in organisms fixed 

 with Flemming's fluid and stained wirli iron-ha^niatoxylin. 

 Gross always found the chambered structure present after 

 fixation Avith corrosive sublimate, but he attributes this 

 structure to the action of the fixative. 



I believe that another explanation is correct. I believe 

 that the invisibility of the chambered structure after fixation 

 with Flemming's fluid is the direct result of the action of the 

 fixative. It is often exceedingly difficult to obtain good 

 differentiation of the internal structure of Bacteria after they 

 have been fixed with Flemming's fluid, and I believe that this 

 is due to the action of the fluid upon the cell-membi-aue and 

 the protoplasm. Every cytologist must have experienced, at 

 some time or other, a difficulty in staining cells after fixation 

 in Flemming's fluid. At all events my own experience leads 

 me to believe that this must be so. I would also point out 

 that, in the case of C. veneris, not only does a prolonged 

 action of osmic vapour — in the course of fixation — cause a 

 change in the staining reactions of the granules, but it also gives 



^ This statement requires some qualification. For although Schellack 

 describes the chi'omatin as being in the form of granules ("Die 

 Kummer\vnnde scheinen aus einer festeren Substanz zu bestehen und 

 es sind ihnen Kornchen aufgelagert," p. 400), he seems inclined in 

 another place to regard the nucleus as being constituted by the whole 

 of the substance of the chamber walls. He says : " Die Gesamtheit der 

 Waben in einer normaien Spirochaite bildet einen ziemlich fest in sicli 

 haltljaren, komjxikten Stab, den sogenannten Kernstali. Die PeripList- 

 hiille liegt ihm direkt auf," etc. (p. 40l). 



