124 
Proceedings of the Royal Society of Edinburgh. [Sess. 
Table XXXIY. 
Name of Bone. 
Length in mm. of Bone of 
Average 
Percentage of 
Excess of 
Length. 
A, Control. 
B, Castrated 
Bitch No. 1. 
C, Castrated 
Bitch No. 2. 
Femur 
Tibia 
15 
50 
15-5 
54 
15-5 
54 
33 
8 
Another observation upon the effects of castration upon the skeleton of 
dogs is recorded by Brian (21). He compared the weight of the skeletons 
of castrated animals with the weight of the skeletons of controls, with 
result shown in Table XXXY. 
Table XXXY. — Comparison of the Weight of the Skeleton of Castrated 
Animals with the Weight of the Skeleton of Controls. 
Average weight of skeleton of castrated animals . . 240 grammes. 
Average weight of skeleton of control animals . . .175 „ 
Percentage of excess of weight ...... 18*7 „ 
Summary of the Observations. Group B, 1-3. 
In animals which have been castrated there is — 
1. An increase in the length and weight of the bones. 
This increase tends to affect especially the more distal segments of the 
limb. Exceptionally, it affects the proximal segment more than the distal. 
This occurred in the hind limb of one capon and one castrated dog, and in 
three fore limbs of two castrated guinea-pigs. In each of the two exceptional 
hind limbs the absolute growth was greater in the more distal segment. In 
the case of the three guinea-pig fore limbs the absolute growth was less in 
the more distal segment. 
2. There is a delay in the obliteration of the epiphysial cartilages. 
The second of these results is important, and it is desirable to emphasise 
it. As the result of observations (22), (23), (24) in the slaughter-house, it has 
been found that a bull’s epiphyses have joined the bone shafts by the time the 
animal is 2 years old, whereas in the bullock the process of endochondral 
ossification is not completed until the animal is 3 or even 4 years old. 
These facts show that the disturbance in the proportions of the limbs, 
and the undue prolongation of the process of ossification which takes place 
in the absence of functioning sexual glands, may fairly be ascribed to the 
metabolic effects of an uncomplicated testicular failure. That this is 
really so, and that not only may the changes in the limbs, but also the 
