ORGANIC EVOLUTION — PHYSICAL ZO 



evolution in this or that respect — in the St. Bernard of 

 size, in the mastiff of strength, in the greyhound of 

 speed, in the bulldog of courage ; but on the whole the 

 tendency has been towards retrogression — a retrogres- 

 sion which has operated unequally on the animal parts, 

 physical and mental, and has not infrequently been 

 concomitant with partial evolution. To this unequal 

 retrogression, combined in some cases with limited 

 evolution, is probably to be attributed the diversity of 

 shapes and capacities which characterize our many 

 domesticated breeds. Thus the lapdog and the pug 

 are probably examples mainly of retrogression, not 

 evolution; probably their peculiarities of shape and 

 character are due mainly to the fact that man has 

 permitted or caused retrogression in them in certain 

 directions by selecting the most degenerate individuals 

 in these respects, at the same titoe that he has checked 

 retrogression, and even caused some evolution, in other 

 directions. Thus also the bulldog has undergone 

 retrogression as regards size, but evolution as regards 

 courage ; the greyhound retrogressed as regards 

 strength and power of scent, but evolved as regards 

 speed ; the St. Bernard has gained in size, but lost in 

 speed ; and so also with all other breeds. 



Dogs among civilized peoples especially have often 

 been the mere playthings of their owners, who, taking 

 unconscious advantage of the tendency towards 

 retrogression, have gratified their caprices by rearing 

 many grotesque vaiieties. As regards the equidse and 

 bovidse the case has been entirely different. Reared 

 almost solely for use, their powers and capabilities 

 preserved to the utmost, the domesticated varieties 

 show little retrogression and some evolution. But 

 suppose we selected a number of the swiftest race-horses, 

 or the largest dray-horses, or the best milk-giving cows, 

 and bred from them, selecting afterwards in succeeding 



