MEN DELI AN INHERITANCE IN RABBITS 363 



on the average in one in four of their offspring. These whites 

 mated with each other produce only white offspring, while the 

 black are as usual of two kinds, pure blacks and impure blacks. 

 Similarly, as Professor Castle has shown, a rough coat is dominant 

 over a smooth coat, and a short coat over a long coat. 



Rabbits. — Hurst paired white Angora rabbits (with pink eyes 

 and silky hair) with " Belgian hare " rabbits (with pigmented 

 skin, dark eyes, and short yellow fur). The hybrids were pig- 

 mented like the " Belgian hares," but the fur was grey like that 

 of the wild rabbit. These hybrids were inbred, and 14 distinct 

 types resulted — an apparent " epidemic of variation " to which 

 Mendel's theory has supplied the clue, for four pairs of contrasted 

 characters are involved in the hybrid inbreeding — namely, short 

 hair versus long hair, pigmented coat versus albinos, grey versus 

 black coat, uniform versus marked coat (Dutch marking latent 

 in the albinos), and the 14 distinct types illustrate the possible 

 combinations. 



As regards short hair versus long hair, Hurst found that when 

 the short-coated hybrids were inbred they produced short-haired 

 forms like the Belgian hare grandparent, and long-haired forms 

 like the Angora grandparent. Out of 70 which reached the age of 

 two months or more, 53 were short-haired and 17 long-haired — a 

 close approximation to the Mendelian anticipation, 52*5 : ly^. 

 Similarly, as regards pigmented coat versus albino, the hybrids, 

 when inbred, yielded 132 pigmented and 39 albino forms — a 

 close approximation to the Mendelian expectation, 129 : 43 ; 

 and so on. 



Cats. — There are some interesting results as to colour (Don- 

 caster). Thus, " pure " orange ? crossed by " pure " black 6 

 gives tortoiseshell females and yellow males, but black ? crossed 

 by orange S gives black males or females, tortoiseshell females, 

 and orange males. It seems that orange usually dominates over 

 black in males, while in females the orange (for some unknown 

 reason) is less dominant and tortoiseshell results. Male tortoise- 



