PLATE 3 
EXPLANATION OF FIGURES 
26 Spermatid with the reticular nucleus. 
27 to 33. Successive transformation stages of the spermatid up to the forma- 
tion of the nucleus with granular appearance and loose consistency. 
34 Wandering of the centrosome into the nucleus. 
35 Centrosome imbedded within the nucleus. 
36 Appearance of a vacuole in the cytoplasm. 
37 and 38 The vacuole enlarges; the nucleus diminishes its size and its stain- 
ing activity increases. 
39 Division of the centrosome. 
40 Two daughter centrosomes lying apart from each other. 
41 Two daughter centrosomes contained in a common clear space. 
42 Change of the shape of the nucleus. 
43 Consistency of the nucleus changing into homogeneous, the change ad- 
vancing from the peripheral part centrad. 
44 Change of consistency of the nucleus completed; the proximal centrosome 
undergoing transformation. 
45 Proximal centrosome transformed into rod shape while associating with 
its fellows. 
46 Spermatid of about the stage shown in figure 44 viewed from the top. 
47 to 50 Nearly mature spermatozoa; the proximal centrosome lies in the 
axis of the perforatorium; the vacuole containing the distal centrosome lies in 
figure 47, within the main part of the head; in figure 48, within the perforatorium, 
while in figures 49 and 50 on the boundary between the two: in figures 47 and 48 
the head shows a granular appearance, while in figures 49 and 50 it is perfectly 
homogeneous; in cytoplasm is a chromatoid body. 
51 Mature spermatozoon. 
