On the Dimegalous Sperm and Cliromsomal Variation of Eusdiistus, etc. 125 
cell nuclei in tlie \ncinity of the spermatocytes of the growtli period (the 
period wliere the dimegaly of these germ cells first manifests itself), and 
front eacli such portion of each foUicle I drew the largest nucleus present. 
This was done without determining whether the greatest diameter of a 
nurse cell nucleus lay in the section drawu, for that would have involved 
very much additional labor. Such drawings were made on 41 sections of 
three different testes, with the foUowing results, the numbers given repre- 
senting the number of cases: 
Follicle 
Largest Nucleus 
Next Largest Nucleus 
1 
27 
6 
2 
0 
0 
3 
9 
21—22 
4 
1 
3 
5 
17 
4 
6 
3 
5 — 6 
Though the method used was far front precise it gives the result that 
the largest nurse cell nuclei occur in follicles 1 and 3 in 87,9% of all cases, 
the next largest in follicles 1 and 3 in Qö,6%, while in not a single section 
was the largest nurse cell nucleus found in follicle 2. Now when we recall 
that the spermatocytes of follicles 1 and 3 are the largest of all, and 
those of follicle 2 the smallest, a significant coiTespondence beconies evi- 
dent : the largest nurse cell nuclei are associated with the largest sperma- 
tocytes, the smallest with the smallest spermatocytes. The actual volu- 
minal differences of the nurse cell nuclei are to be seen in fig. 37, PL X: 
on the left side of the figure are seen five nurse cell nuclei (/, n) of follicle 1, 
and on the right one such nucleus of follicle 2, this figure presenting a 
fair example of the average differences. The proportion of largest nurse 
cell nuclei in follicles 1 and 3 would probably have been greater had I 
taken pains to draw the greatest actual diameter of each. 
Whether the size of the body of a nurse cell varies directly vdth 
the size of its nucleus was not decided for reasons stated. But from what 
we know of ceU metabolism in general we may conclude that in a homo- 
geneous group of ceUs one with a larger nucleus is more active than one 
with a smaUer. There can also be little question that these nurse ceUs 
are providers of food for the germ ceUs. It would then foUow that those 
nurse ceUs with larger nuclei are the most active in elaborating food ma- 
terial for the spermatocytes, and the difference in the size of the sperma- 
tocytes be then due directly to such differences of the nurse cells. 
