SUPPORTERS OF TELEGONY 77 



however, latterly came to the conclusion that telegony 

 only occurred rarely, and some years before his death 

 expressed the opinion that it was ' a very occasional 

 phenomenon.' Agassiz believed in telegony. He was 

 strongly of opinion 



1 that the act of fecundation is not an act which is limited in 

 its effect, but that it is an act which affects the whole system, 

 the sexual system especially; and in the sexual system the 

 ovary to be impregnated hereafter is so modified by the first 

 act that later impregnations do not efface that first impression. 



Romanes also believed that telegony occasionally 

 occurred. He paid a good deal of attention to the 

 matter, commenced experiments in the hope of settling 

 the question, and corresponded at length on this 

 subject with professional and amateur breeders and 

 fanciers. The result of his investigations led him to 

 the conclusion ' that the phenomenon is of much less 

 frequent occurrence than is generally supposed. In- 

 deed, it is so rare that I doubt whether it takes place 

 in more than i or 2 per cent, of cases.' He adds 

 that his professional correspondents regard this as an 

 absurdly low estimate. Tegetmeier and Sutherland 

 believe that telegony exists in dogs and other animals ; 

 and Captain Hayes, whose opinion probably coincides 

 with that of the majority of veterinary surgeons, takes 

 for granted that it occurs in horses. A controversy 

 some years ago in the Contemporary Review shows us 

 that Mr. Herbert Spencer was a firm upholder of tele- 

 gony, and that he had a theory of his own as to the 

 mode in which it is brought about. 



The explanations put forward by the supporters of 

 telegony as to the mechanism by which it is effected 

 differ widely. It will be well to discuss them here. 

 The view that telegony is due to the mental im- 

 pression of the dam, held by Sir Everard Home and 

 many others since his day, has nothing to support it ; 



