ALLEGED CASES 147 



to a former ancestor may at any moment occur, it will, I think, be 

 admitted that, for the purpose of testing the ' infection ' doctrine, 

 the dog, of all our domestic animals, is the least satisfactory." Mr. 

 C. H. Lane, discussing toy spaniels in his book. All about Dogs, 

 says, " I have been told by breeders that they have had in one litter 

 a specimen of all four breeds [i.e. of King Charles, Prince Charles, 

 Blenheim, and Ruby spaniels]. In the same way rough and smooth 

 terriers often occur in the same litter, not because of infection, but 

 because of reversion." 



Cats. — Dr. H. de Varigny tells of a normal cat which, after pro- 

 ducing kittens to a Manx cat, had several tail-less kittens to an or- 

 dinary cat {Journal des Debals, Septemher gth, 1897; cited by Ewart, 

 1 901). But the mother, or the second father, or both, may have had 

 a tail-less ancestor, to which some of the kittens happened to revert. 

 Or even if there were no such ancestor, the tail-lessness may have 

 been merely a variation that happened to coincide with the pecu- 

 liarity of the first sire, but was not in any way due to him. For 

 tail-lessness is not a very rare " sport." 



As a counter-case, Prof. Ewart refers to " a pair of young cats, 

 of a somewhat peculiar variety, obtained from Japan. These cats 

 belonged to a small breed, bluish in colour, with the exception of the 

 ears and extremities, which were black. When the female grew up 

 she first had kittens to a common tabby cat. These kittens showed 

 the characteristic tabby markings. Her next kittens were by her 

 Japanese mate, but in no respect did they suggest the previous 

 tabby-coloured mate. No better experiment than this could be 

 made with cats. The imported breed was quite distinct, and yet 

 not sufficiently prepotent to swamp the common domestic English 

 cat. Yet, though the first litter was sired by a common tabby, there 

 was no indication whatever of the previous tabby mate in her second 

 and pure-bred litter." (Case cited by Sydney Villar, F.R.C.V.S., 

 Proc. Nat. Vet. Assoc. 1900, p. 130.) 



Sheep. — Dr. Alexander Harvey, in a paper " On a Curious Effect 

 of Cross-breeding " (1851), gives on the authority of W. McCombie 

 of Tilliefour, Aberdeenshire, the following case : 



Six pure-bred black-faced horned ewes were put, in the autumn 

 of 1844, some to a Leicester ram (white-faced and polled), and others 

 to a Southdown ram (dun-faced and polled), and produced cross- 

 bred lambs. 



In the autumn of 1845 the same ewes were put to a pure black- 



