118 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
gonia staining like those of the apical cell. Grinberg (:03) has given 
a detailed account of the apical cell in a number of Lepidoptera and 
has come to the conclusion that it has two, more or less distinct, 
functions. He agrees with La Valette St. George, in opposition to 
Toyama, that it is a germ cell, but one which has become modified 
for an entirely different function. In the embryo and young larva 
the apical cell is closely applied to the testicular wall at the distal end 
of the follicle. Later the cell enlarges and between it and the sur- 
rounding spermatogonia can be seen a lighter area filled with cyto- 
plasm containing numbers of deeply staining granules. He believes 
this area to be formed by the disintegration of primary spermatogonia 
which were directly in contact with the apical cell, and that the remains 
of these cells, after being elaborated by the apical cell, serve as nutri- 
ment for the remaining spermatogonia. Somewhat later the apical 
cell moves into the lumen of the follicle, but for a time remains attached 
to an ingrowth of the testicular wall. This connection with the outer 
wall of the testis is probably retained to enabie the cell to procure 
nutritive material, which it elaborates for the use of the spermatogonia. 
This view is supported by the fact that the cytoplasmic granules often 
show a radiate arrangement, as though streaming out from the nu- 
cleus to the surrounding spermatogonia. Griinberg (:03, p. 378) con- 
cludes: “Thre Thatigkeit als solche kann eine doppelte sein: durch 
Aufnahme von Material und Verarbeitung desselben. iibt sie eine 
assimilirende 'Vhitigkeit aus; ausserdem kann sie durch selbstiindige 
Produktion von Nahrsubstanz die Bedeutung einer secernirenden Ndhr- 
zelle gewinnen.”’ Recently Cholodkovsky (:05) has changed his former 
view and accepts Griinberg’s conclusions. 
In the Orthoptera the appearance of the apical cell suggests that it 
has a similar function, although the evidence is far from conclusive. 
It is possible that this cell is concerned in the formation of the mito- 
chondrion, since this substance in the primary spermatogonia closely 
resembles the finely granular material surrounding the nucleus of the 
apical cell. In this connection it is interesting to note that the primary 
spermatogonia, although dividing rapidly, are always of approximately 
the same size, while the secondary spermatogonia rapidly decrease in 
size in the later generations. 
2. THEr SPERMATOGONIAL AUTOSOMES. 
It has long been known that there is often considerable variation 
. . 5 3 ma ‘ = 
in the size of the different chromosomes in the’same species, but it 
