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H. E. Jordan 
scribes as the type for spermatogenetic and somatic mitoses. It is very 
difficult to imagine a reason for so fundamental a difference as Bigelow 
believes to obtain between the spermatocyte and oöcyte mitoses in the 
Same animal form. Moreover, in the final stage of the oöcyte studied and 
figiired by Bigelow the maturation chromosomes are not yet fuUy for- 
med; and it is possible that a subsequent further relationship between 
the chief nucleolus and the chromosomes may be assumed of which there 
is as yet no intimation, unless possibly the vacuolization described or the 
diminishing basophile staining reaction evident with the iron-hema- 
toxylin stain biit apparently without significance as revealed by extrac- 
tion of stain and subsequent subjection to Auerbach’s mixture. From 
numerous and widely different sources the e^ddence accumulates that 
nucleoli contain something necessary for the formation of the chromo- 
somes. 
The true and full nature of this relation between chromosomes and 
nucleoli cannot yet be discerned, but the above facts add to the cumu- 
lative evidence respecting the partial function of the nucleolus as a store- 
house of at least some of the constituent elements of chromosomes, it 
may be a nutritive substance. In Crihrella the chromosomes consist of 
a red-staining (in Auerbach’s stain) ground substance onto which the 
nucleolar buds (green) pass and with which they become incorporated. 
It is suggested, though impossible of verification, that the „ground sub- 
stance“ (linin?) may contain the essential element of the chromosome, 
and that the chromatic constituent is a secondary (nutritive?) substance. 
Boveri’s^) law deduced from a study of the size relations of the 
ceUs and their nuclei in sea-urchin larve (developed by parthenogenesis 
or merogany and mechanical treatment, i. e. shaking shortly after ferti- 
lization so as to produce cells with half and twice the specific number of 
chromosomes respectively) and formulated as follows: »Die Größe der 
Larvenzellen ist eine Funktion der in ihnen enthaltenen Chromatinmenge, 
und zwar ist das Zellvolumen der Chromosomenzahl direkt proportional« 
(p. 74), receives partial confirmation from a comparison of the egg of 
Asterias forbesii with those of the two species above mentioned. In re- 
spect to size the eggs and nuclei of Cribrella and EcMnaster are very appro- 
ximately identical. Their nuclei have a diameter of about 300 microns 
and the eggs vary from 500 to 800 microns. The egg of Asterias has a 
diameter of about 100 microns and its nucleus varies from 40 to 50 mi- 
1) Boveri, Th. Zellenstudien V. Über die Abhängigkeit der Kemgröße und 
Zeilenzahl der Seeigellarven von der Chromosomenzahl der Ausgangszeilen. Jena. 1905. 
