152 Transactions of the Society. 



particles on the whole outside of the nuclear membrane, soon 

 becoming heaped at many places into larger clusters, so that they 

 form striking, scaly masses in the immediate neighbourliood of the 

 nucleus. This emission process persists for a fairly long time. 

 Nucleus and cell body increase simultaneously in volume." 



These quotations from Schaxel's work may be taken as typical. 

 Two obvious objections may be raised against his interpretation : 

 (1) Schaxel produces not one jot or tittle of evidence that the 

 granular particles are chromatin ; and (2) he has not shown satis- 

 factorily that the granules come from the nucleus at all. 



Now with regard to the first objection it will at first seem 

 natural enough, from the point of view of the older technique, to 

 regard such an extranuclear basophil mass as emitted chromatin, 

 but modern work on the mitochondria of the female germ cell 

 allows us to look at the facts from quite another point of view, for 

 just such appearances as Schaxel figures are produced by the 

 mitochondria at certain sta^^^es of oo2;enesis. 



We further believe that certain at least of the appearances 

 figured by Schaxel as chromophil granules flattened upon and 

 adhering to the nuclear membrane, are artifacts produced by the 

 inferior fixation methods employed. Even with non-acetic chrome 

 osmium fixation bad preparations are occasionally produced in 

 which a granular appearance of the nuclear membrane is to be 

 seen. The mitochondria during their dispersal through the egg 

 cytoplasm become very fine, and we have little doubt that fixatives 

 of unsuitable osmotic pressure would cause those grains near the 

 nuclear membrane to be driven into or upon the latter so as to 

 produce the appearance found by Schaxel. 



Schaxel, moreover, has not used the methods which best dis- 

 criminate between chromatinic and non-chromatinic matter. He 

 falls into the error of relying far too much on the original Flemming 

 acetic mixture and iron alum h^ematoxylin method. Schaxel is 

 not the possessor of a unique technique unknown and unattainable 

 by other w^orkers ; he simply uses methods which are now known 

 to be inadequate to reveal many important cytoplasmic constituents, 

 and which can be employed by any zoologist. 



Eecent w^orkers such as Hirschler, Weigl, Nussbaum-Hilarowitz 

 and ourselves do not find true chromatin behaving in the manner 

 Schaxel describes. It is true tliat in rare cases, such as in insect 

 and some other eggs (;?, 17), a definite formation of presumably 

 true cliromatin particles is found in the egg cytoplasm, and several 

 observers trace these granules as originating from the nucleus 

 (nucleolus), but similar cases are rare. These definite cytoplasmic 

 chromatin granules are to be distinguished from such " emitted " 

 granules (mitochondria) as have erroneously been described as 

 chromatin by Schaxel. 



