RESULTS OF CASTRATION 



29 



definitely that heat does not occur in the hedgehog when 

 postpuberally castrated. 



A great number of observations have been made on the 

 growth of the skeleton in the castrated mammal. These 

 observations have shown that different parts of the skeleton 

 react to castration in a different manner. This explains why 

 the skeleton as a whole has other proportions than normally, 

 and even each single bone. As in man, so also in certain 

 mammals the bones of the extremities are longer, this having 

 been shown by measurements on guinea pigs and rabbits. 



Fig. 18. — Profile of normal and castrated cows. Normal, 

 average of 100 animals; castrated, average of 

 eleven animals. — From Tandler and Keller. 



though the differences may not be very significant, as in the 

 experiments of Moore (1922) on guinea pigs. As in man 

 this phenomenon is presumably caused by the more prolonged 

 persistence of the zone of proliferation. Observations on 

 the skeleton after castration have been made also on the 

 dog, sheep and ox. The observations of Tandler and Keller, 

 who measured a great number of normal and castrated cows 

 and bulls, are very important. They found striking differences 

 in the height of the normal and of the castrated cow. Out 

 01 eleven castrated cows ten attained a height of 140 cm. or 

 more; out of 250 normal animals only four attained this height 

 (Fig. 18). The greater height is due to the longer extremities. 

 Very careful investigations have been made also on the 

 skull of the castrated mammal. Tandler and Keller (1910) 

 stated that the very striking sexual divergences in the size 



