8 N. H. AGR. EXPERIMENT STATION. [Bulletin 160 



ably reduced by castration; but the degree depends much on the 

 age at which the operation is performed, as is likewise the case 

 with other animals. Merino rams have large horns, whilst the 

 ewes 'generally speaking are without horns'; and in this breed 

 castration seems to produce a somewhat greater effect, so that 

 if performed at an early age the horns 'remain almost undevel- 

 oped.' On the Guinea coast there is a breed in which the females 

 never bear horns, and, as Mr. Winwood Reade informs me, the 

 rams after castration are quite destitute of them." 



Darwin's deduction is that castration, so far as horns is 

 concerned at least, leads to a return to the primal condition of 

 the animals, since, as he states, "horns of all kinds, even when 

 they are equally developed in the two sexes, were primarily 

 acquired by the male to conquer other males, and have been 

 transferred more or less completely to the female." 



The relation between the potency of horn growth and the 

 presence of the male sex-gland, is not yet altogether determined. 

 Nor can it be until the effects of spaying, or removal of the 

 ovaries, of Dorset Horn and Merino ewes are worked out. No 

 experiments, so far as the writer can discover, have ever been 

 pursued in this regard. At present writing I have just spayed 

 three Dorset Horn and three Rambouillet ewe lambs. The 

 results will be watched with interest and will be recorded and 

 published in a subsequent paper. It is possible that in regard 

 to the Dorset Horn the horn may receive a rigid check in devel- 

 opment, in which case it would be apparent that upon the fore- 

 going assumption the female sex-gland also influences or aids 

 growth; or, perhaps, the horn may assume a ram-like appearance 

 in similar fashion as sterilized females of the human family produce 

 a heavy growth of hair on the face. Should the horn remain 

 normal, then it will point strongly to a potent influence of virility. 



The interpretation offered by Wood to explain the peculiar 

 inheritance of horns in sheep, in accordance with the data which 

 he obtained by crossing Dorset Horns with Suffolk Downs and 

 which I have previously reviewed, is that the horned character 

 appears dominant in the male but recessive in the female. 

 Bateson,* in examining these facts has drawn the conclusion: 

 "Sex itself acts as a specific interference, stopping or inhibiting 

 the effects of a dominant factor, and it is not a little remarkable 

 that the inhibition occurs always, so far as we know, in the 

 female, never in the male." He admits, however, the difficulty 

 in distinguishing between this probability and the other possi- 

 bility; namely that the male provides a stimulating factor. But 

 discussing further in this connection he makes this statement: 

 "Since the condition can be developed in males, it is evident 

 that maleness itself is not a necessary complement; and it is not 



* Bateson, W., 1900, "Mendel's Principles of Heredity." Cambridge, England, University Pres?. 



