746 



SCIENCE 



[N. S. Vol. XXIX. No. 749 



that they were thoroughbred, and were brought 

 from England to Nova Scotia by an English 

 gentleman for the purpose of crossing them to 

 produce a dog for farm purposes. 



I had occasion to observe both dogs care- 

 fully for a considerable period, and I also 

 owned one of the pups for several years. The 

 pups were born in June, 1894. I am, of 

 course, aware of the dangers of collecting post 

 facto data and have therefore included here 

 only such facts as I can verify with certainty 

 from my own recollection. The data given 

 under " legs and body " and " shape of head " 

 are of course only general impressions of a 

 probably more or less blended condition. 



The accompanying table shows some of the 

 contrasting characters in the parents and the 

 offspring. The most striking contrasts are 

 afforded by the color and character of the 

 coats, the presence and absence of the tail, 

 and its variability in the offspring, and by the 

 dispositions, that of the mother being very 

 gentle and timid, while the father had the 

 aggressive collie disposition. The litter con- 

 tained more than sis pups, but these are the 

 only ones which can now be sharply and defi- 

 nitely characterized. It is a noteworthy fact 

 that several of them are in pairs which are 

 very closely alike, differing markedly in only 

 one character so far as observed. Numbers 1 

 and 2 were alike except in color, one having 

 the general color of the mother, and the other 

 that of the father but without any tan. Num- 

 bers 3 and 4 constituted another very clearly 

 marked pair, differing widely from the others 

 in many characters and yet so closely alike 

 that they were scarcely distinguishable, except 

 in their dispositions, which were quite unlike. 

 This recalls some cases of identical human 

 twins. These animals were not of the same 

 sex, however. 



In comparing the characters of the offspring 

 with those of the parents it will be seen that 

 in no character was there complete dominance 

 of one parent in all the offspring. In coat 

 color the father dominated in all but two, in 

 one of which (No. 2) the color was that of the 

 mother. The long, shaggy coat, covering the 

 face and legs as well as the body, appeared in 

 Nos. 1 and 2 of the offspring, except that the 



effect of the wavy hair of the father was also 

 more or less evident. In No. 5 the coat more 

 nearly resembled the father, but in Nos. 3, 4 

 and 6 was quite unlike either parent, being 

 short, smooth and sleek. The differences in 

 eye color may not be significant, as the collies' 

 eyes range from light to dark brown, and in 

 the sheep dogs a wall eye is not uncommon 

 and is considered typical of the breed. 



The inheritance of the tail character is of 

 considerable interest, showing as it does a 

 range from the long bushy tail of the father 

 to a condition approaching its complete ab- 

 sence as in the mother. The intermediate 

 tail lengths can not be attributed wholly to 

 inheritance from the father, however, for dogs 

 with more or less of a tail are said to occur 

 frequently in the pure sheep-dog breed. How 

 the tailless condition originated appears to be 

 unknown, although various statements and 

 conjectures are made in dog books concerning 

 this matter. Two breeds of bob-tailed collie, 

 with tails 5-10 cm. long but otherwise in every 

 particular like the collie, are recognized in 

 certain parts of England' (II., p. 440). 

 Walsh' says (p. 221): 



Until within the last half-century sheep dogs 

 without tails were exempt from taxation, it being 

 supposed that no one would keep a tailless dog 

 who could afford to pay the tax. As a conse- 

 quence almost every sheep dog had its tail cut off, 

 and owing to this cause the tailless sheep dog, 

 still met with in some localities, is supposed to 

 have arisen. ... It is far more probable that the 

 bob [in pointers] is derived from a cross with 

 the bull dog, which is subject to the natural loss of 

 tail in a greater or less degree, and was probably 

 used to give courage to the pointer. . . . Usually 

 these "bobs" [the old English sheep dog] are 

 strongly made and symmetrical dogs, but without 

 any definite type ; they have frequently a tendency 

 to the brindle colour, which favours the theory of 

 the derivation of short tails from the bull dog 

 though it cuts equally against a similar derivation 

 in the pointers, in whom the brindle is absolutely 



' " Dogs of All Nations," 2 vols., London, 1905, 

 illustrated. 



' Walsh, J. H., " The Dogs of the British Islands, 

 etc.," 5th edition, London, 1886, pp. 292, illus- 

 trated. 



