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Show '94 'l'HE PERPETUATION 01!' LIVING BEINGS, have to mention, however, is a very extensive one. It is one that, for want of a better name, has been called "spontaneous variation; " which means that when we do not know anything about the cause of ,phenomena, we call it spontaneous. In the orderly chain of causes and effects in this world, there are very few things of which it can be said with truth that they are spontaneous. Certainly not in these physical matters,- in these there is nothing of the kind,-everything depends on previous conditions. nut when we cannot trace the cause of phenomena, we call the1n spontaneous. Of these variations, multitudinous as they are, but little is known with perfect accuracy. I will n1ention to you some two or three cases, because they are very Temarkable in themselves, and also because I shall want to use them afterwards. Reaumur, a famous French naturalist, a great many years ago, in an essay which l1e wrote upon the art of hatching chickens,-which was iudeed a very curious essay,- had occasion to speak of variations and n1onstrosities. One very re-, markable case had come under his notice of a variation in the form of a human member, in the person of a Maltese, of the name of Gratio I{elleia, who was born with six fingers upon each hand, and the like n urn her of toes to each of his feet. That was a case of spontaneous variation. Nobody knows why he was born with that number of fingers and toes, and as we don't know, we call it a case of "spontaneous" variation. There is another remarkable case also. I select these, because they happen to have been observed and notecl HEREDITARY 'fRA~S::\IISSION AND VARIATION. 95 very carefully at the time. It frequently happens that a variation occurs, bnt the persons who notice it do not take any care in noting down the particulars, until at len<rth when inquiries come to be made, the exact ::J ' circumstances are forgotten; and hence, multitudinous as may be such "spontaneous" variations, it is exceedingly difficult to get at the origin of them. The second case is one of which you may {iud the whole details in the " Philosophical Transactions" fot· the year 1813, in a paper communicated by Coloucl Humphrey to the President of the Royal Society," On a new Variety in the Breed of Sheep,'~ giving an account of a verv remarkable breed of sheep, which at one time was well known in the northern states of America, and which went by the name of the Ancon or the Otter breed of sheep. In the year 1791, there was a farmer of the name of Seth \iVright in 1\1assachusetts, who had a flock of sheep, consisting of a ram and, I think, of some twelve or thirteen ewes. Of this flock of ewes, one at the breeding-time bore a lamb which was very singularly formed; it had a very long body, very short legs, and those legs were bowed ! I will tell you by-and-by how this singular variation in the breed of sheep came to be noted, and to have the prominence that it now has. For the present, I mention only these two cases; but the extent of variation in the breed of animals is perfectly obvious to any one who has studied natural history with ordinary attention, or to any person who compares animals with others of the same kind. It is strictly true that there are never any two specimens which are exactly alike |