SPERMATOGENESIS— INSEMINATION 183 



and Plonnis ^ have also described experiments in which they 

 successfully inseminated dogs by artificial methods (see p. 

 611). Heape ^ has recorded a series of experiments carried 

 out by Sir Everett Millais on the artificial insemination of 

 Basset hounds. The present writer has succeeded in inducing 

 pregnancy by this method in a Dandie Dinmont terrier. More- 

 over, there are numerous cases on record in which dogs have been 

 successfully inseminated artificially as a means of overcoming 

 certain forms of barrenness (see p. 611). The method adopted in 

 all these experiments was substantially the same as that em- 

 ployed by Spallanzani. 



Artificial insemination is now also practised on mares, donkeys, 

 and cows, and usually with the object of remedying sterihty. 

 In thoroughbred mares especially it has proved of great service, 

 having been the means of preserving for breeding purposes many 

 valuable animals which otherwise would have been discarded.^ 



IwanofE * has described experiments in which pregnancy was 

 induced in rabbits and guinea-pigs by the artificial injection of 

 testicular fluid into the female generative passages. The same 

 investigator states that he induced hybridisation between 

 a male rat and a female mouse by artificially inseminating 

 the latter (see p. 611, Chapter XIV.). 



He has shown, further, that the spermatozoa retain their 

 vitality sufficiently long to admit of their being employed 

 successfully in artificial insemination if they are kept in solutions 

 of various salts (sodium chloride, sodium carbonate, &c.) or in 

 serum instead of in the secretions of the accessory generative 

 glands. Hunter appears to have been the first to practise arti- 



' Plonnis, "KUnstliche Befruchtung einer Hiinden," &o., Inaug. Dissert., 

 Rostock, 1876. •" Heape, loc. cit. 



' For references to particular experiments see Heape, " Tiie Artificial 

 Insemination of Mares," Veterinarian, 1898 ; also a booklet published by 

 Huish (The Cause and Remedy of Sterility in Mares, Cows, and Bitches, 

 London, 4th Edition, 1899), in which a large number of cases are described 

 in which artificial insemination was successfully carried out ; also IwanofE, 

 " De la Fecondation Artifioielle chez les Mammiferes," Arch, des Sciences 

 Biologiqioes, vol. xii., 1907. The last-mentioned paper contains an account 

 of a very large series of experiments on horses, cows, and sheep, with a 

 full description of the practical methods employed, and a very complete 

 account of the literature of the subject. 



" IwanofE, "La Fonctiou des Vdsicules s^minales," &c,, Jour, de Phys. et 

 de Path, gen., vol. ii., 1900. 



