98 HEREDITY [CH. 



It was formerly believed, and the belief is still firmly 

 held by fanciers and animal breeders, that if a female 

 of one breed bears young by a male of another breed, 

 and is then mated with a male of her own kind, the 

 ofispring of this second mating will in some cases 

 show the influence of the first sire, and instead of 

 being pure-bred will in some respects be mongrels 

 resembling the mongrel offspring of the first mating. 

 The instance of this made classical by Darwin is 

 'Lord Morton's Mare,' in which a chestnut mare bore 

 a colt by a quagga, and afterwards two colts by a 

 black Arab stallion, both of which were dun-coloured, 

 and bore stripes on the legs and in one colt on the 

 neck also [7]. But it is known that dun horses are 

 frequently striped to some extent, and Ewart's 

 well-known work with zebras [11], in which it was 

 attempted to repeat this experiment, gave negative 

 results. The belief in telegony is widely held among 

 dog-fanciers, and many cases could be quoted, but 

 whenever properly controlled experiments have been 

 made, no evidence of telegony has been forthcoming. 

 The belief in it is almost certainly due to the habit 

 of generalising from individual instances ; whenever 

 a case occurs which appears to favour the belief, it is 

 adduced as proof, even though other causes may have 

 been operative, and matings in which no evidence for 

 it appears are passed over in silence. If it were 

 a genuine phenomenon, it is almost certain that 



