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Show THE PERPETUATION o :F LIVI~G llEINGS, case a further development of tl1at abnormal type. You see it is only in the fourth, in the person of 1VIaTie, that the tendency, when it appears but slightly in the second generation, is washed out in the third.r while the progeny of Andre, who escaped in the first instance escape altogether. 'Ve h'a ve in this case a good example of nature' s tendency to the perpetuation of a variation. I-Iere it is certainlv a variation which carried with it no use or benefit; and yet you see the tendency to perpetuation may be so strong, that, notwithstanding a great admixture of pure blood, the variety continues itself up to the third generation, which is largely marked with it. In this case, as I have said, there was uo 1neans of the second generation intcnnarrying with any but five-fingered persons, and the question naturally suggests itself, What would have been the result of such marriage? Reaumur narrates this case only as far as the third generation. Certainly it would have been an exceedingly curious thing if we could have traced this 1natter any further; had the cousins intermarried, a. six-fingered variety of the human race might have been set up. To show you that this supposition is by no means an unreasonable one, let n1e now point out what took place in the case of Seth Wright's sheep, where it happened to be a matter of moment to him to obtain a breed or raise a flock of sheep like that accidental variety that I have described-and I will tell you wl1y. In that part of Massachusetts where Seth vV right was living, the fields were separated by fences) and the HEREDITARY TltANSMISSION AND VARIATION. sheep, which were very active and robust, would roam abroad, and without much difficulty jump over these fences into other people's farms. As a matter of course, this exuberant activity on the part of the sheep constantly gave rise to all sorts of quarrels,. bickerings, and contentions among the fanners of the neighbourhood; so it occurred to Seth Wright) who was, like his successors, more or les · 'cute, that if he could get a stock of sheep like those with the bandy legs, they would not be able to jump over the fences so readily, and he acted upon that idea. He killed his old ram, and as soon as the young one arrived at maturity, he bred altogether from it. The result was even n1ore striking than in the human experiment which I 1nentioned just now. Colonel II umphreys testifies that it always happened that the offspring were either pure Aneons or pure ordinary sheep; that in no case was there any mixing of the Ancons with the others. In consequence of this, in the course of a very few years) the farmer was able to get a very considerable flock of this variety, and a large number of them were spreacl throughout 1\1assachusetts. l\1ost unfortunately, however-! suppose it was because they were so common- nobody took enough notice of them to preserve their skeletons ; and although Colonel IIumphrey states that he sent a skeleton to the president of the Royal Society at the same ti1ne that he forwarded hi ::; paper, and I am afraid that the variety has entirely disappeared; for a short time after these sheep hacl· become prevalent in that district) the Merino sheep |