30 



Mr. F. H. A. Marshall. On the Effects of [Dec. 20, 



the head. The rams' horns are much better developed.* The Scotch 

 Blackfaced sheep are similar.-j- 



With Herdwicks, which are the breed used in the investigation described 

 below, the rams have large coiled horns and the ewes are hornless. It must 

 be mentioned, however, that at the Eelldale Association Show last year, at 

 Eskdale, a very small proportion of the Herdwick rams present were without 

 horns, but this condition is very unusual. Moreover, according to informa- 

 tion given by Mr. John Eothery, of Wastdale Head, Westmorland, the ewes 

 may very occasionally have scurs, though their occurrence is far less 

 frequent than formerly. The ewes at the Norwich Show were without any 

 sort of scurs, but the rams were typically horned. Mr. Eothery informs 

 me further that Herdwick ram lambs are, as a rule, castrated when six 

 weeks old, and do not then grow horns, but if the testes are removed at 

 a later age, horns with some degree of development are present. The 

 skull of the Herdwick wether has been described by Shattock and 

 Seligmann,J who say that it resembles the skull of the ewe in general 

 configuration, being less rugged than the skull of the ram, while the bones are 

 thinner and the cranial cavity does not extend so far forward as in the ram. 



Two Herdwick ram lambs, born in the late spring, were sent to Cambridge 

 from Westmorland in August, 1910. Each of these had horns between 

 2 and 3 inches in length. One of these was kept as a control, and now 

 possesses large coiled well-developed horns. The other was castrated when 

 about three months old. In the case of the latter the horns ceased to grow,, 

 and in the following spring became loose (apparently as a consequence of 

 being butted by the ram), and eventually came off, leaving low rounded 

 knobs, representing the horn cores. The wether is still alive, but no new 

 horns have developed. 



Two more Herdwick ram lambs, born in May, 1911, were castrated in the 

 following autumn, one when about four months, the other when about 

 five months old. In the former case the horns were about 4£ inches long, and 

 have since remained stationary. In the latter case the horns were 6 inches 

 long, and likewise have since ceased to grow. In another lamb, which has 

 not (as yet at any rate) been castrated, the horns are now (December, 1911} 

 11 inches long. 



It would appear, therefore, that not only does the development of horns in 



* I am indebted to Mr. W. Kalph Peel for a series of photographs illustrating horn, 

 growth in Lonk rams, wethers, and ewes of various ages. 



t It has been thought worth while to relate the facts mentioned above since they do- 

 not appear to be recorded in any of the literature on sheep. 



+ Shattock and Seligmann, " Observations upon the Acquirement of Secondary Sexual 

 Characters," ' Eoy. Soc. Proc.,' 1904, vol. 73. 



