126 
Thos. II. ^lontgomery, jr. 
Ccrtain it is that the dimogaly of the spcriu cells is occasioned by 
some outsklc influence diiring tlicir early growth period. for the sperma- 
togonia of a giveii gciieratioii exhibit no appreciable differences among 
tliomselves. And sincc the diniegaly is a voluminal difference it must be 
referable to a difference in the food supply, and this in turn to size (con- 
sequently amonnt of activity) of the niirse cell nuclei. This seems a 
consistent and satisfactory answer to the probleni. 
Thus far wc have considered only the phenomenon of the dimegaly 
and the reason for the differences in total cell volume; it is now in place 
to compare the behavior of the different constituents of the cells. When 
we compare spermatocytes at the end of the growth period. one fronr 
follicle 2 (fig. 9. PI. X) and one from follicle 3 (fig. 17), we find the size 
differences of the nuclei are relatively less than those of the cell bodies^). 
The chromatin mass of the nuclei appears relatively constant, it is the 
karyolymph that differs in amount in spermatocytes of different sizes, 
conscquently the larger nuclei appear clearer than the smaller. The 
niantle fibres, those that connect the chromosomes with the centrosomes, 
are of nuclear origin, and their mass is relatively greater in the larger sper- 
matocytes (fig. 18) than in the smaller (fig. 10), though again the volu- 
niinal differences of these fibres is not as great as that of the cytoplasm. 
But most remarkable is the fact, that 1 pointed out eleven years ago, 
that despite differences in the cell volumes the chromosonie sizes remain 
constant! If one compares chromosomes of the first maturation division 
of large spermatocytes (PI. IX, figs. 1 — 3, 18) and of small spermatocytes 
(figs. 10, 11, 30, 34) no appreciable size differences are noticeable; the 
same relation is to be seen also in figs. 57 and 58 of PI. X. This comes 
out equally clearly on comparing chromosomes of the second maturation 
spindle from the large cells (figs. 23) and those of the small (fig. 12). The 
nuclei of the early spermatids are larger in the large spermatocytes (fig. 6) 
than in the small (fig. 13) but it is a difference in amount of the karyo- 
1) Within any nucleus of tliis stage there is to be seeii besides the linin net- 
work witli the cluomatin upon it, a diplosome or niodified chromosome (e) as well 
as a true plasraosome (p). Though I have described these structures before I mention 
them again because Foot and Strobell (1909. The Nucleoli in the Spermatocytes and 
Genninal Vesicles of Eu^chistus variolarius. Biol. Bull. 16) have denied the conconii- 
tant presence of both of these organs in these cells, and have scarcely considered my 
(letailed descriptions of them. Evddently either their method of smear preparations 
produced a collapse of the plasmosome, or eise they did not employ an adequate stain- 
ing method. With the safranine-gentian violet stain of Hermann plasmosome and 
diplosome may be shaiqdy differentiated. 
