266 The Reproductive Powers of Domesticated Animals. 



I have known cases in which heifers which could not breed were 

 exercised daily, by being led about for a certain length of time ; 

 but this treatment is seldom sufficient to reduce those accumula- 

 tions which impede generation. Highly satisfactory results 

 have been gained by a thorough change of climate, when the 

 stock were sent to hilly districts where the air is bracing, and 

 they have to take plenty of exercise. 



Barrenness may also be traced to too close relationship, or a 

 similarity of temperament. This is, however, a qualified bar- 

 renness, to be overcome by proper selection on the part of the 

 breeder. The fat condition of the male animal, and his want of 

 constitutional vigour, are frecjuontlv the chief causes of difficulty. 

 I have known of bulls, which had become valueless for breeding 

 purposes, being worked upon the land in carts, and thereby 

 rendered serviceable. 



I Ijelieve that we have the condition of successful repro- 

 duction very much under our own control, and that the cases 

 of legitimate barrenness, either on the part of the male or female, 

 are much more rare than we imagine. I know that animals 

 which are naturally capable of breeding can be rendered in- 

 competent by adopting a special course of treatment ; and I 

 consider that in our usual system of management we very much 

 retard and interfere with the healthy performance of this natural 

 function of animal life. 



For the purpose of more fully investigating the causes of 

 barrenness, I have examined* the ovaries of several heifers which 

 were, after very careful trial, condemned and killed as barreners ; 

 and I have every reason to believe that by far the larger pro- 

 portion were naturally quite competent for breeding, and that in 

 the majoritv of cases nonimpregnation arose from the seminal 

 fluid never reaching the ovum, which was ready for fertilisation, 

 or from that fluid not being of a healthy character. In some cases 

 in which the ova were to all appearance perfectly healthy, the 

 tubes — whereby the seminal fluid should have been conveyed — 

 were so overcharged with fatty matter that impregnation was ren- 

 dered impossible. In other cases the ovaries were in an unhealthy 

 condition, either one or both having to a great extent wasted 

 away. Sometimes one of the ovaries had been suffering from 

 atrophy, and the other in such an irritable and sensitive con- 

 dition that it might be almost described as inflamed ; and under 

 such circumstances the formation of a healthy ovum could 

 scarcely be expected. In other instances the ovaries had become 

 considerably enlarged, in consequence of a fatty degeneration of 



* In the prosecution of this examination, I have received great assistance from 

 Dr. Atchley of Bristol, to whom my best thanks are due. 



