274 J. B. GATENBY AND J. H. WOODGER 
5. GENERAL DESCRIPTION OF THE BEHAVIOUR OF THE INCLU- 
SIONS OF THE CYTOPLASM IN CAVIA SPERMATOGENESIS. 
We have compiled the following descriptions, and also 
Pl. 12, after a personal study of many preparations of guinea- 
pig testes, and also after a careful examination of the literature 
of the subject. The works of Niessing (24), Meves (20), Brown 
(2), Benda (1), v. Lenhossék (18), Moore (22), and Stockard 
and Papanicolaou (26), have been considered especially with 
reference to the formation of the acrosome. Regaud (27) 
and Duesberg (6) have also been consulted and their various 
statements examined. A good many of our results are quite 
new, especially with reference to the Golgi apparatus. 
6. Pertiop I. Growing Spermatocyte. 
The mitochondria and Golgi apparatus are to be found in 
the so-called germinal epithelial cells ; during the growth of 
the spermatogonium, the mitochondria, which hitherto tended 
to surround the region of the archoplasm, become spread 
throughout the cytoplasm, while the Golgi apparatus and 
archoplasm increase in size. Some time before the spermato- 
eyte has become full-grown the archoplasm becomes distin- 
suishable into two regions—an outer clearer part, and an inner 
chromophile part formed by the proacrosomic material. 
In Pl. 12, fig. 5, is drawn the spermatocyte just about to 
begin the first maturation division. The chromosomes are 
appearing within the nucleus and are connected to one another 
here and there by chromatic or linin filaments. Throughout 
the cytoplasm the mitochondria (m) are scattered haphazardly. 
At cup is the enigmatic chromatoid body, which later may be 
found in each spermatid, and which apparently therefore may 
divide during cell-division. The Golgi apparatus and the 
archoplasm are at gz. By this stage the inner region of the 
archoplasm containing the proacrosomic material has resolved 
itself into a large number of discrete granules which have been 
ficured by Moore, Meves, Niessing, and Stockard and Papani- 
colaou, and which we propose to call the proacrosomic granules 
