CYTOPLASMIC INCLUSIONS OF THE GERM-CELLS 291 
show thickenings. The mitochondria have left the periphery and are 
collecting towards the middle of the posterior end of the cell. 
Fig. 12.—The Golgi apparatus has left the head end of the cell, and is 
beginning to regain its spherical shape. The centrosome apparatus and 
flagellum have moved up towards the posterior end of the nucleus. From 
this region of the latter manchette fibres (Mc) begin to grow back. The 
acrosome become plastered over the entire front of the nucleus. Nearly 
all the mitochondria have left the anterior pole of the cell. 
Fig. 13.—Later stage showing great development of the outer zone of 
the acrosome (ozA). The manchette has become tubular (mc). From the 
spermatid Golgi apparatus (GA) has begun to grow out a small bead 
(GAX) which later forms the middle-piece Golgi apparatus. The mito- 
chondria are collecting in the region of the manchette. The centrosome 
ring is beginning to pass from the posterior part of the nucleus. 
Fig. 14.—The acrosome become more oval in contour. The centrosome 
ring is passing near the Golgi apparatus (c?). From the latter the middle- 
piece Golgi apparatus bead is just separating (GAX). The manchette is 
less evident, and around the axial filament or flagellum a distinct thicken- 
ing is visible. It was not settled whether the parts in figs. 13 and 14, 
MC and MD, were inter-related, 
Fig. 15.—The acrosome is now fully formed. The nucleus has gained 
its characteristic shape. The middle-piece Golgi bead (GAx) has become 
fixed to the middle-piece (mp) just behind the nucleus, The mitochondria 
begin to become attached to the middle-piece skeleton (mp) from before 
backwards. The Golgi apparatus is drifting down and undergoes staining 
changes. 
Fig. 16.—Spermatozoon viewed edgewise, just before skinning off of 
residue bead. The middle-piece bead is at Gax, but not all the mito- 
chondria (m) have become applied to the middle-piece skeleton ; in the 
residue protoplasm many of the mitochondria run together and undergo 
changes, forming von Ebner’s granules (mx). The Golgi apparatus is 
degenerating. 
NO, 258 Xx 
