The Variation of Animals and Plants under Domestication — Volume 1. Darwin Charles

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СКАЧАТЬ difficulties, but these difficulties relate chiefly to subjects — such as the degree of perfection of the geological record, the means of distribution, the possibility of transitions in organs, etc. — on which we are confessedly ignorant; nor do we know how ignorant we are. If we are much more ignorant than is generally supposed, most of these difficulties wholly disappear. Let the reader reflect on the difficulty of looking at whole classes of facts from a new point of view. Let him observe how slowly, but surely, the noble views of Lyell on the gradual changes now in progress on the earth's surface have been accepted as sufficient to account for all that we see in its past history. The present action of natural selection may seem more or less probable; but I believe in the truth of the theory, because it collects, under one point of view, and gives a rational explanation of, many apparently independent classes of facts. (Introduction/4. In treating the several subjects included in the present and my other works I have continually been led to ask for information from many zoologists, botanists, geologists, breeders of animals, and horticulturists, and I have invariably received from them the most generous assistance. Without such aid I could have effected little. I have repeatedly applied for information and specimens to foreigners, and to British merchants and officers of the Government residing in distant lands, and, with the rarest exceptions, I have received prompt, open-handed, and valuable assistance. I cannot express too strongly my obligations to the many persons who have assisted me, and who, I am convinced, would be equally willing to assist others in any scientific investigation.)

      CHAPTER 1.I

       DOMESTIC DOGS AND CATS.

       ANCIENT VARIETIES OF THE DOG. RESEMBLANCE OF DOMESTIC DOGS IN VARIOUS COUNTRIES TO NATIVE CANINE SPECIES. ANIMALS NOT ACQUAINTED WITH MAN AT FIRST FEARLESS. DOGS RESEMBLING WOLVES AND JACKALS. HABIT OF BARKING ACQUIRED AND LOST. FERAL DOGS. TAN-COLOURED EYE-SPOTS. PERIOD OF GESTATION. OFFENSIVE ODOUR. FERTILITY OF THE RACES WHEN CROSSED. DIFFERENCES IN THE SEVERAL RACES IN PART DUE TO DESCENT FROM DISTINCT SPECIES. DIFFERENCES IN THE SKULL AND TEETH. DIFFERENCES IN THE BODY, IN CONSTITUTION. FEW IMPORTANT DIFFERENCES HAVE BEEN FIXED BY SELECTION. DIRECT ACTION OF CLIMATE. WATER-DOGS WITH PALMATED FEET. HISTORY OF THE CHANGES WHICH CERTAIN ENGLISH RACES OF THE DOG HAVE GRADUALLY UNDERGONE THROUGH SELECTION. EXTINCTION OF THE LESS IMPROVED SUB-BREEDS.

       CATS, CROSSED WITH SEVERAL SPECIES. DIFFERENT BREEDS FOUND ONLY IN SEPARATED COUNTRIES. DIRECT EFFECTS OF THE CONDITIONS OF LIFE. FERAL CATS. INDIVIDUAL VARIABILITY.

      The first and chief point of interest in this chapter is, whether the numerous domesticated varieties of the dog have descended from a single wild species, or from several. Some authors believe that all have descended from the wolf, or from the jackal, or from an unknown and extinct species. Others again believe, and this of late has been the favourite tenet, that they have descended from several species, extinct and recent, more or less commingled together. We shall probably never be able to ascertain their origin with certainty. Palaeontology (1/1. Owen 'British Fossil Mammals' pages 123 to 133. Pictet 'Traite de Pal.' 1853 tome 1 page 202. De Blainville in his 'Osteographie, Canidae' page 142 has largely discussed the whole subject, and concludes that the extinct parent of all domesticated dogs came nearest to the wolf in organisation, and to the jackal in habits. See also Boyd Dawkins, 'Cave Hunting' 1874 page 131 etc. and his other publications. Jeitteles has discussed in great detail the character of the breeds of pre-historic dogs: 'Die vorgeschichtlichen Alterthumer der Stadt Olmutz' II. Theil, 1872 page 44 to end.) does not throw much light on the question, owing, on the one hand, to the close similarity of the skulls of extinct as well as living wolves and jackals, and owing, on the other hand, to the great dissimilarity of the skulls of the several breeds of the domestic dogs. It seems, however, that remains have been found in the later tertiary deposits more like those of a large dog than of a wolf, which favours the belief of De Blainville that our dogs are the descendants of a single extinct species. On the other hand, some authors go so far as to assert that every chief domestic breed must have had its wild prototype. This latter view is extremely improbable: it allows nothing for variation; it passes over the almost monstrous character of some of the breeds; and it almost necessarily assumes that a large number of species have become extinct since man domesticated the dog; whereas we plainly see that wild members of the dog-family are extirpated by human agency with much difficulty; even so recently as 1710 the wolf existed in so small an island as Ireland.

      The reasons which have led various authors to infer that our dogs have descended from more than one wild species are as follows. (1/2. Pallas, I believe, originated this doctrine in 'Act. Acad. St. Petersburgh' 1780 Part 2. Ehrenberg has advocated it, as may be seen in De Blainville's 'Osteographie' page 79. It has been carried to an extreme extent by Col. Hamilton Smith in the 'Naturalist Library' volumes 9 and 10. Mr. W.C. Martin adopts it in his excellent 'History of the Dog' 1845; as does Dr. Morton, as well as Nott and Gliddon, in the United States. Prof. Low, in his 'Domesticated Animals' 1845 page 666, comes to this same conclusion. No one has argued on this side with more clearness and force than the late James Wilson, of Edinburgh, in various papers read before the Highland Agricultural and Wernerian Societies. Isidore Geoffroy Saint-Hilaire ('Hist. Nat. Gen.' 1860 tome 3 page 107), though he believes that most dogs have descended from the jackal, yet inclines to the belief that some are descended from the wolf. Prof. Gervais ('Hist. Nat. Mamm.' 1855 tome 2 page 69, referring to the view that all the domestic races are the modified descendants of a single species, after a long discussion, says, "Cette opinion est, suivant nous du moins, la moins probable.") Firstly, the great difference between the several breeds; but this will appear of comparatively little weight, after we shall have seen how great are the differences between the several races of various domesticated animals which certainly have descended from a single parent-form. Secondly, the more important fact, that, at the most anciently known historical periods, several breeds of the dog existed, very unlike each other, and closely resembling or identical with breeds still alive.

      We will briefly run back through the historical records. The materials are remarkably deficient between the fourteenth century and the Roman classical period. (1/3. Berjeau 'The Varieties of the Dog; in old Sculptures and Pictures' 1863. 'Der Hund' von Dr. F.L. Walther, Giessen 1817 s. 48: this author seems carefully to have studied all classical works on the subject. See also Volz 'Beitrage zur Kulturgeschichte' Leipzig 1852 s. 115, 'Youatt on the Dog' 1845 page 6. A very full history is given by De Blainville in his 'Osteographie, Canidae.') At this latter period various breeds, namely hounds, house-dogs, lapdogs, etc, existed; but, as Dr. Walther has remarked, it is impossible to recognise the greater number with any certainty. Youatt, however, gives a drawing of a beautiful sculpture of two greyhound puppies from the Villa of Antoninus. On an Assyrian monument, about 640 B.C.,an enormous mastiff (1/4. I have seen drawings of this dog from the tomb of the son of Esar Haddon, and clay models in the British Museum. Nott and Gliddon, in their 'Types of Mankind' 1854 page 393, give a copy of these drawings. This dog has been called a Thibetan mastiff, but Mr. H.A. Oldfield, who is familiar with the so-called Thibet mastiff, and has examined the drawings in the British Museum, informs me that he considers them different.) is figured; and according to Sir H. Rawlinson (as I was informed at the British Museum), similar dogs are still imported into this same country. I have looked through the magnificent works of Lepsius and Rosellini, and on the Egyptian monuments from the fourth to the twelfth dynasties (i.e. from about 3400 B.C. to 2100 B.C.) several varieties of the dog are represented; most of them are allied to greyhounds; at the later of these periods a dog resembling a hound is figured, with drooping ears, but with a longer back and more pointed head than in our hounds. There is, also, a turnspit, with short and crooked legs, closely resembling the existing variety; but this kind of monstrosity is so common with various animals, as with the ancon sheep, and even, according to Rengger, with jaguars in Paraguay, that it would be rash to look at the monumental animal as the parent of all our turnspits: Colonel Sykes (1/5. 'Proc. Zoolog. Soc.' July 12, 1831.) also has described an Indian pariah dog as presenting the same monstrous character. The most ancient dog represented on the Egyptian monuments is one of the most singular; it resembles a greyhound, but has long pointed ears and a short curled tail: a closely allied variety still exists in Northern Africa; for Mr. E. Vernon Harcourt (1/6. 'Sporting in Algeria' СКАЧАТЬ