290 J. B. GATENBY AND J. H. WOODGER 
So far as possible we have utilized the work of previous observers. All 
the figures are drawn to scale excepting fig. 16, in which the tail of the 
sperm is much shorter than it should be. 
Fig. 5.—Ripe spermatocyte, 1, in the prophases of the first maturation 
division, chromosomes appearing in the nucleus. The Golgi complex 
contains in the middle the divided centrosome (c). Around the latter are 
the proacrosomic granules (APG) which constitute the inner zone of the 
archoplasm. Between the Golgi elements or dictyosomes (GE) which lie 
on the surface of the archoplasm, and the inner region of the archoplasm, 
is a space free of proacrosomic granules. The space constitutes the outer 
zone of the archoplasm. The whole Golgi complex is drawn in optical 
section. In the ground cytoplasm lie the mitochondria (mM) and _ the 
chromatoid body (CHB). 
Fig. 6.—Second spermatocyte division metaphase viewed from side. 
The mitochondria lie haphazardly around the spindle. Following 
Papanicolaou and Stockard we have drawn the proacrosomic granules 
(their idiogranulomes) as preserving their individuality and becoming 
distributed here and there in the cytoplasm around the spindle (apa). 
Fig. 7.—Newly-formed spermatid showing the same elements as the 
spermatocyte in fig. 5, only the proacrosomic granules are now surrounded 
by the archoplasmic vacuoles (v.v.). The centrosome is dividing. The 
mitochondria tend to pass to the periphery of the cell. 
Fig. 8.—Later stage: the Golgi complex begins to move towards the 
anterior pole of the cell. The proacrosomic granules have fused one with 
another till only three are left, the large main one in the middle (APG) 
being surrounded by its archoplasmic vacuole (v.v.). The mitochondria 
tend to lie on the periphery of the cell. The centrosome has divided into 
two, and from one part the flagellum is growing out. 
Fig. 9.—Golgi complex and part of nucleus of later spermatid. The 
proacrosomic granules have all run together to form the proacrosome 
(PRA), lying in the archoplasmic vacuole (v); the proacrosome is differen- 
tiated into an outer (0ZA) and an inner zone (1ZA). The proacrosome has 
left its position in the middle of the archoplasm and has approached the 
nuclear membrane (N). 
Fig. 10.—Later spermatid, after the proacrosome has become partly 
flattened against the nuclear membrane. The outer and especially the 
inner zones (OZA, IZA) of the acrosome have become much larger. The 
Golgi apparatus and archoplasm surround the entire acrosome. The 
archoplasmic vacuole has begun to grow down on each side of the nucleus 
(Lev). The Golgi complex is placed to one side of the nucleus, but in later 
stages the acrosome comes to lie at the head end of the nucleus, possibly 
by a partial rotation of the latter. 
Fig. 11.—Spermatid at a later stage just before the Golgi apparatus 
flows away from the acrosome. The front and back parts of the nucleus 
