1911.] 



Castration and Ovariotomy upon Sheep. 



2 ( J 



neck ring, much claret colour on the breast, and other characters which are 

 typically male. The voice, however, still remained that of the female, and 

 the colour of the bill and some of the feathers also continued unchanged. 

 Goodale suggests that the bird in question in course of time may assume the 

 complete secondary sexual characters of the drake. 



Apart from these cases there appears to be no definite experimental 

 evidence, at least from among vertebrates, of the assumption of male 

 characters as a result of ovariotomy. 



Observations and Experiments upon Sheep. 



The various breeds of sheep differ considerably in regard to horn growth. 

 Some are horned in both sexes, though the degree of development of the 

 horns varies according to sex (whether ram, wether, or ewe) ; some are 

 hornless in both sexes, while others, again, are horned in the male, but 

 hornless in the female. At the Eoyal Agricultural Society's Show, at 

 Norwich, last summer, I made some observations upon representatives 

 of most of the British breeds. Among those breeds which are ordinarily 

 described as hornless, the males of the following in many cases had rudi- 

 mentary horns or " scurs " : — Hampshire Down, Suffolk, Lincoln, Leicester, 

 Derbyshire Gritstone, Cotswold, Devon Longwool, Dartmoor, and Cheviot. 

 (The rams of the last-mentioned breed had particularly large scurs, which 

 almost amounted to horns in some individuals.) On the other hand, the 

 ewes of these breeds in no case had any scurs. Wethers were not repre- 

 sented at the Norwich Show, but it would seem from other observations and 

 enquiries relating to some of the above-mentioned breeds that the scurs do 

 not generally appear in the rams until they are more than a year old, and 

 that the wethers do not grow them at all. 



In those breeds which are horned in both sexes the horns of the ewes are 

 less perfectly developed than those of the rams. Thus, in Dorset Horns, the 

 ewes' horns are finer and lighter than the tups', and, as a rule, do not curl 

 .so much. The wethers' horns are either more or less intermediate, or 

 resemble those of the ewes. Dorset ewes are born without horns, but the ram 

 lambs generally have incipient horns which are visible at birth. It is note- 

 worthy that the horns of the wethers are most like those of the ewes when 

 they are castrated early, and that postponement in castration diminishes the 

 resemblance.* In the Lonk sheep the ewe and wether are not unlike in their 

 horns, but those of the wether are rather more contracted and grow closer to 



* These statements are based on personal observation or on information obtained from 

 breeders in the Isle of Wight. 



