A Supplementary Letter on the Identity of the Species of the Dog, Wolf, and Jackal; From John Hunter, Esq. F. R. S. Addressed to Sir Joseph Banks, Bart. P. R. S.

XV. A supplementary Letter on the Identity of the Species of the Dog, Wolf, and Jackal; from John Hunter, Esq. F. R. S. addressed to Sir Joseph Banks, Bart. P. R. S. Read April 30, 1789. Sir, In the year 1787 I had the honour of presenting to this learned Society, a Paper to prove the Wolf, the Jackal, and the Dog to be of the same species. But as the complete proof of the Wolf being a Dog, which consisted in the half-bred puppy breeding again, had not been under my own inspection, although sufficiently well authenticated, I saved a female of one of the half-bred puppies, mentioned in that Paper, in hopes of being myself a witness of the fact; but when the period of impregnation arrived, we unluckily missed that opportunity. However, another half-bred puppy has had young, which is equally satisfactory to me as if my own had bred. John Symmons, Esq. of Milbank, has had a female Wolf in his possession for some time, who was lined by a Dog, and brought forth several puppies, which I had the honour of seeing with you. This was a very short time after the brood had been produced by Mr. Gough's Wolf, the subject of my former Paper, therefore the puppies were nearly of an age with mine. These puppies Mr. Symmons has reared; only one of them was a female, and she had much more of the mother or Wolf in her than any of the the rest of the same litter. I communicated my wish to Mr. Symmons, that either his puppy or mine should prove the fact to our own knowledge; which he immediately, with great readiness, acceded to. On the 16th, 17th, and 18th of December, 1783, this bitch was lined by a Dog, and on the 18th of February she brought eight puppies, all of which she now rears. If we reckon from the 16th of December, she went sixty-four days; but if we reckon from the 17th, the mean time, then it is sixty-three days, the usual time for a bitch to go with pup. These puppies are the second remove from the Wolf and Dog, similar to that given by my Lord Clanbrassil to the Earl of Pembroke, which bred again. (See Philosophical Transactions, Vol. LXXVII. p. 255.) It would have proved the same fact if she had been lined by either a Wolf, a Dog, or one of the males of her own litter. I may just remark here, that the Wolf seems to have only one time in the year for impregnation natural to her, and that is in the month of December; for every time Mr. Gough's Wolf has been in heat was in this month, and it proves to be the same month in which Mr. Symmons's Wolf was in heat; for his half-bred Wolf is nearly of the same age with mine, and the time she was in heat was also the same with that of her own mother, and the present brood corresponds in time with the brood of Mr. Gough's Wolf. I am, &c. JOHN HUNTER.