Letter received by Banks from Marmaduke Tunstall, 28 June1785 (Series 72.187) - No. 0004

[Page 4]

occur, could never think that nature in any one instance could so constantly deviate from it's usually established laws, as to make it an universal rule, that whenever twins of different sexes were produced, one should always prove a free-martin & incapable of propagation:  luckily in the year 1782 I had an opportunity of trying the fact.  One of my cows having brought forth 2 calves male & female to my no small pleasure, the cow-calf I carefully preserved & in contradiction to Mr. J. Hunter's opinion who asserts they shew not the least inclination for the bull, had the pleasure to find mine follow the laws of nature & expressed her desires for the bull as early, if not earlier than most of her species, she has not as yet indeed, owing to her age, been permitted to take the bull, but propose it the next time she is proper for it, and I doubt not I shall be able to inform you next year she has produced a calf, which I think as a matter of fact argument must have some weight against at least the universality of Mr. J. Hs sentiments, in some deference to them, must mention the year after by extraordinary good luck, tho' I have not a large dairy