376 SCIENCE PROGRESS 



done. If the artificial feeding is excessive, and the sheep are 

 made to depend for the rest of the year {i.e. during gestation and 

 afterwards) upon nothing better than sustenance diet, one might 

 reasonably expect the ewes to deteriorate, and their subsequent 

 fertility to be impaired. It is apparently for such a reason as 

 this that some breeders, especially in England, regard the 

 practice of flushing as altogether to be deprecated. In this 

 connection it should be mentioned that there is some evidence 

 for the belief that if sheep are flushed in one year, the process 

 must be repeated in the next, and that if this practice is not 

 adopted, the ewes tend to be less fertile than if they had never 

 been flushed at all. 



On the other hand, certain of the reports show that sheep 

 which produce twins one year, in a large proportion of cases 

 bear twins also in the 3'ear following. This appears to occur 

 irrespectively of flushing. It would seem, therefore, that an 

 increased degree of fertility is a characteristic of certain 

 particular ewes. 



Before concluding this brief summar}'- of recent investigation 

 upon certain of the factors which control fertihty, I may take 

 this opportunity of urging the importance of further inquiry 

 in the interests of the livestock industr3^ In these da3^s, when 

 much is heard of agricultural depression, it is not alwaj^s 

 realised that the breeding of domestic animals is one of the 

 staple industries of the country. The prominent position which 

 British horses, British sheep, and British cattle still hold in the 

 livestock markets of the world is, perhaps, the most hopeful 

 indication for the future of British agriculture. It is a sufficiently 

 remarkable fact that, excepting for the Holstein cattle, the Per- 

 cheron horses, and the Merino sheep, all the prominent breeds 

 of livestock throughout the world have their foundation in 

 animals of British ancestry. 



Even the Percheron horses are not the equals of the English 

 Shires for stamina and power. Nearl}^ ever^^ good horse on the 

 Continent and in America is derived from British stock. The 

 famous American trotters are descended from English hackney's. 

 At the international conference of sheep-breeders which 

 recently met at Ipswich, great stress w'as laid upon the high 

 favour in which British sheep are alwa3's held by the great 

 cosmopolitan bu3'ers. The livestock export from Great Britain 

 goes on increasing 3'ear b3' 3'ear, and last 3'ear was phenomenal, 



