VOL. LXXVII.] PHILOSOPHICAL TRANSACTIONS. 205 



The times of uterine gestation being the same in all the varieties of every 

 species of animals, this circumstance becomes necessary to determine a species. 

 The affinity between the fox, wolf, jackal, and several varieties of the dog, in 

 their external form and several of their properties, is so striking, that they ap- , 

 pear to be only varieties of the same species. The fox would seem to be a 

 greater remove from the dog than either the jackal or wolf, at least in disposi- 

 tion, not being either so sociable respecting its own species or man, but natu- 

 rally a solitary animal: from all which I should suspect it is only allied to the 

 dog by being of the same genus. It is confidently asserted by many that the 

 fox breeds with the dog, but this has not been accurately ascertained; but if it 

 had, it would probably have been carried further, and once breeding, according 

 to what we have said, does not constitute a species ; this however is a part I 

 mean to investigate. Wolves and jackals are found in herds ; and the jackal is 

 so little afraid of the human species, that, like a dog, it comes into houses in 

 search of food, more like a variety of the dog in consequence of cultivation 

 than chance. It is by much the most familiar of the two; for we shall find 

 hereafter, that in its readiness to copulate with the dog, and its familiarity with 

 the dog afterwards, it is somewhat different from the wolf. The wolf then 

 being an animal better known in Europe, where inquiries of this kind are made, ^ 

 some pains has been taken to ascertain, whether or not it was of the same spe- 

 cies with the dog; but I believe it has been hitherto considered as only belong- 

 ing to the same genus. 



Accident often does as much for natural history as premeditated plans, especi- 

 ally when nature is left to itself. The first instance of the dog and wolf 

 breeding in this country seems to have been about the year 1766. A Pomera- 

 nian bitch of Mr. Brookes's, in the New Road, was lined only once by a wolf, 

 and brought forth a litter of 9 healthy puppies. The veracity of Mr. Brookes 

 is not to be doubted, respecting the bitch beings lined by a wolf; yet, as it was 

 possible she might have been lined by some common dog without his knowledge, 

 the fact was not clearly made out; but it has been since ascertained that the dog 

 and wolf will breed. Several noblemen and gentlemen bought some of the 

 puppies, as I was informed by Mr. Brookes. My Lord Clanbrassil purchased a 

 bitch-puppy ; and Mr. Brookes presented one to me, which I kept for observa- 

 tions and experiment. Its actions were not truly those of a dog; it had more 

 quickness in attending to things, was more easily startled, as if particularly 

 apprehensive of danger, quicker in transitions from one action to another not 

 so ready to the call, being less docile; and from these peculiarities it lost its life 

 being stoned to death in the streets for a mad dog.* 



• Hearing that Lord Clanbrassil's bitch had bred. Sir Joseph Banks was so obliging as, at my re- 

 quest, to write to his LordshiOj who sent the following account : 

 VOL. XVI. M M 



