8 ROBERT H. BOWEN 
I have also found in the spermatids a collection of granules 
which seem to be preserved best in the absence of acetic acid. 
During the formation of the acrosome these granules are arranged 
in a circle around the acroblast and lie close to the nuclear 
membrane. This arrangement is a constant and striking one 
(fig. 4). The nature and fate of these granules are not known. 
Possibly they are related to the chromatoid bodies of other 
animals. They may be related to the granules previously men- 
tioned as occurring in the spermatocytes. A more critical study 
of these granules will be undertaken on new material. 
Summary 
1. The acrosome of the urodele sperm arises as in many other 
animals from the Golgi apparatus plus idiosome (acroblast), 
which is later cast off and remains for some time in the cytoplasm 
near the base of the sperm nucleus. 
2. The middle-piece of the sperm is derived from the so-called 
proximal centriole, and is not, as McGregor claimed, “chiefly 
derived from the remnant of the sphere.”’ 
3. The origin of the filament on the free edge of the undulating 
membrane of the sperm tail from one part of the originally bipar- 
tite proximal (?) centriole is suggested as a possibility. 
COLEOPTERA 
My observations on the Coleoptera are confined to a single 
species, Lixus concavus Lec., which was examined merely to 
check up the origin of the acrosome in the light of my previous 
work on Hemiptera. In this beetle, the Golgi apparatus is pres- 
ent in the spermatocytes in the form of numerous scattered 
Golgi bodies (fig. 27) similar in a general way to those which I 
have described in the pentatomids. I have not followed out the 
preliminary history of these Golgi bodies or their distribution in 
the maturation divisions. In the early spermatids, however, 
before the mitochondria have condensed to form the nebenkern, 
the Golgi bodies are easily demonstrated, scattered irregularly 
in the cytoplasm (fig. 28). They gradually draw together (fig. 
29), and eventually fuse to form a single mass (fig. 30), the acro- 
