The relation of iiucleoli to chromosomes in tlie egg of Cribrella sanguineolenta etc. 399 
may also be in Echimster, as previously noted and alternatively inter- 
preted. In the absence of actual maturation stages nothing more can 
be said regarding the number and shape of the chromosomes in either 
form. However, at the height of the growth period they exist as beaded 
threads apparently few in number. 
In Cribrella the chromosomes, as far as their chromatin substance 
is concerned, seem to arise froni the nucleolus by a process of badding 
and dispersion — the single primary nucleolus gimng rise to secondary 
Fig. 6. 
More highly magnifled region of illustration number 4, sbowing the relationship between the several 
gradations of nucleoll and the chromosomes. The smallest nucleolar buds are approximately of the size 
of the spheric granules of the chromosomes. In iron-hematoxylin material the nucleoli and spheric 
granulös of the chromosomes are intensely black; in the material stained with the Auerbach's mixture 
these structures are green, and the granules (chromomeres) of the chromosomes are enmeshed in a red- 
staining underlying network of delicate mossy threads. X 1500. 
nucleoli (figs. 4 and 5) and these in turn to tertiary and so on (figs. 6, 7. 
8 and 9) — the final products combining and aligning themselves to 
form the beaded thread-like chromosomes. In Auerbach’s stain the 
spheric granules (clmomomeres?) of the chromosomes stain green, and 
they appear enmeshed in an underlying red-stainig network of plasmatic 
(linin?) threads. 
The nucleoli, then, disappear, at least for the most part, before 
the dissolution of the nuclear wall. The endence here is strongly in 
favor of the nucleolar origin of the chromosomes, and in Opposition to the 
hypothesis of their morphologic individuality. 
26 * 
