EwART — Variation : Germinal and Environmental. 375 



though the crossing of two very distinct human races often leads to disastrous 

 results, intermarriage between members of some of the higher branches of the 

 human family may prove highly beneficial — that, in fact, there may be progress, 

 mental as well as physical, without tlio transmission, so long thought necessary, 

 of definite traits acquired by the nervous, muscular or other systems during the 

 individual lifetime. 



As the combining of two sets of characters in the offspring is probably 

 comparatively rare, it may be taken for granted that it is only possible when the 

 environment is particularly favourable — when the food is plentiful, the assimilation 

 perfect, the germ-cells well nourished and about equally prepotent, and all tlie 

 climatic conditions are pre eminently suitable. 



5. Sometimes new, or at least unexpected, characters appear in the offspring. 

 The grey tailless rabbit was an example of an unexpected character which was 

 certainly not due to reversion— though there may have been tailless rabbits before. 

 Though this is a congenital variation, it is not necessarily a germinal one. In 

 two rabbits that died a few hours after birth, the tail was represented by a 

 shrivelled process about the thickness of a bristle — evidently the tail, normal 

 enough in the young embryo, had atrophied during development. If the tendency 

 to atrophy is inherited, the variation would belong to the germinal and not to the 

 environmental group. 



One of the many kinds of tame mice is a Japanese variety that, whenever it 

 moves, tends to spin round. Last November, I noticed that three out of four of 

 a litter of twenty-one days old rabbits, frequently sjDun round at a great rate. 

 When on the way to their food they would suddenly begin to wheel like a dog 

 after its tail, sometimes from right to left, sometimes from left to right, and they 

 always spin round when disturbed.* The sire of the spinners is a half-wild rabbit, 

 the dam an Angora-Himalaya. The fourth member of the litter is extremely like 

 a wild rabbit in its attitudes as well as in make and colour. Never once has it 

 been observed spinning. 



I shall only mention three otlier instances of variation. In a black rabbit, the 

 offspring of two half- wild rabbits, one of the fore-legs is crooked, as if it belonged to a 

 basset or dachshund. In another, but quite unrelated rabbit — one of the spinners — 

 both fore-legs are so bent that the feet turn inwards as is sometimes the case 

 in short-legged Skye terriers. All these variations have occurred in cross-bred 

 families, but variability also occurs without intercrossing. 



Recently I saw two rooks from a rookery near Edinburgh, which were of a 

 reddish-brown or chestnut tint. If similarly coloured and equally prepotent rooks 

 continue to appear a new variety may be established. 



* Spuming rabbits would have little chance of surviving ia a wild state. 



