220 
ZOOLOGY: D. H. TENNENT 
Proc. N. a. S. 
Following this stage the hyaloplasm sphere divides, as shown by Cham- 
bers, and each portion moves and Hes like a cap on the nucleus at opposite 
poles, and the formation of the asters, accompanied by the transition to 
the gel phase in the cytoplasm, begins. In my material there is evidence 
of a centripetal flowing, as indicated in the orientation of the rods, as this 
reversal occurs. 
What are these rods? They are not mitochondria. The acetic acid 
in the fixing fluid has dissolved these. They are not chromosomes. The 
mass and number of the rods greatly exceed that of the chromosomes. 
I do not believe them to be chromidia, fragments of chromatin lying freely 
in the cytoplasm. 
I believe that they are a coarse precipitate, possibly a synthetic product, 
formed by the action of extruded nuclear enzymes into the cytoplasm, 
and that the processes that I have described are similar to those that occur 
normally, but which cannot be seen under ordinary conditions, for the 
reason that the particles ordinarily formed are below the limits of micro- 
scopic vision. Nor does there seem to be a probability that they could 
be distinguished from other moving colloidal particles if the living egg 
were to be studied with the ultra microscope. It should be emphasized 
that the granules and rods which are visible in this experimental material 
and which I have interpreted as a coarse precipitate, are not formed in 
the straight fertilized eggs. 
Turning now to the explanation of the formation of these particles. 
If we were dealing with solutions of electrolytes the explanation would 
lie probably in the application of von Weimarn's law on the relation be- 
tween concentration of the reaction mixtures to the size of the particles 
of the precipitate. If we compare von Weimarn's microphotographs 
of the precipitates of barium sulphate formed by pouring together solu- 
tions of barium cyanid and magnesium sulphate, with the sections here 
under consideration, a striking similarity to those obtained at concentra- 
tions of 1/500 normal to 1/50 normal will be evident. (Reproductions 
of some of these microphotographs may be found in Ostwald and Fischer, 
Theoretical and Applied Colloid Chemistry, pp. 27-32.) 
But we are dealing with an emulsion colloid, possibly a mixture of sus- 
pensoids with emulsoids. The phenomenon that I have described, the 
formation of granules and rods, is clearly due to a coalescence of particles 
into coarsely dispersed aggregates. 
It seems probable that the suspensoid particles surrounded, "protected," 
by emulsoid particles, coalesce, as a result of dehydration due to an enzyme 
emitted from the nucleus. Inasmuch as the change is reversible and these 
particles pass again into solution the electrical nature of the process is 
also probable. This naturally would be the case if we were dealing with 
a suspensoid fraction. 
Passing from the changes shown prior to and during the first division, 
