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 Debats, September 9th, 1897; cited by Ewart, 

 1 90 1 ). 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 

 i 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 ewe9 were put to a pure black- 



