30 J. BRONTE GATENBY 



It is important to notice that careful modern work on 

 oogenesis confirms certain previous accounts of the extrusion 

 of nucleolar material into the egg cytoplasm, and puts on 

 a definite basis of truth the claim that the nucleus takes a part 

 in the development of the cytoplasm. 



All such positive evidence which we possess in this direction 

 applies to the behaviour of the nucleolus, and 1 do not believe 

 that we are able to point to any circumstances which would 

 lead us to conclude that the chromosomes take a part, though 

 I think that such is the case. Probably the only significant 

 fact upon which we can fall back lies in the formation of 

 fioccuUuit thrcuids and reticula from the chromosomes after 

 the prophases of the heterotypic division, and just before the 

 real inception of the growth period of oogenesis. But this 

 might just as well be interpreted as preparation by the chromo- 

 somes for their own growth by means of substances absorbed 

 from the egg cytoplasm. 



With regard to this difficult matter of the relationship 

 between nucleus and cytoplasm during oogenesis, I beheve that 

 zoologists may be able to ascertain new facts if they develop 

 and use more constantly the various silver-nitrate techniques, 

 which give pictures unobtainable by other methods. 



(p) Schaxel's Chromatin Emission. 



From time to time in these papers I have referred to Schaxel's 

 work on chromatin emission in a number of invertebrates 

 which he has studied. Criticisms which have abeady been 

 brought forward by me, in conjunction with Woodger, are that 

 Schaxel has not worked at his material by proper methods, 

 and he has not attacked the problem from the point of view 

 of the cytoplasmic inclusions. Furthermore, he has not estali- 

 lished that his granules are chromatin or that thev are emitted 

 through the nuclear membrane. With corrosive fixation, &c., 

 and Ehrlich's haematoxylin, the granules are found to be baso- 

 phil, which probably proves nothing with regard to their 

 microchemical nature. A new phase in the problem of Schaxel's 

 work was introduced by Miss van Herwerden, who, by treating 



