says Sir Astley Cooper, "is no uncommon entry in the ledger of the family apothecary."

In the Philosophical Translations for 1813, Colonel Humphreys has given the facts connected with the origin of a new variety or breed of sheep, which throw some light on this curious subject. In the year 1791, one of the ewes on the farm of Seth Wright, in the state of Massachusetts, produced a male lamb, which, from the singular length of its body and shortness of its limbs, received the name of Otter breed. From the curvature of its fore-legs, which caused them to appear like elbows when the animal was walking, Dr. Shuttack termed it Ancon.

This physical conformation incapacitating the animal from leaping fences, appeared to the neighbouring farmers so desirable that they wished it continued. Wright determined on breeding from this ram, and the first year obtained only two, with the same peculiarities. The following years he obtained greater numbers, and when they became capable of breeding with one another, a new and strongly-marked variety, before unknown to the world, was established.

The perpetuation of this variety of sheep appears a sufficient answer to those physiologists who deny the unity of the human species because there are differences between the skeleton of the Negro and that of the Caucasian; but we have instances of more marked varieties being propagated. The Dorking breed of fowls have five toes each, the Hungarian hogs do not divide the hoof, and families are known in which most of the individuals are born with six fingers. The anatomical differences between the Negro and Cau

casian are at the best very minute, indeed they can only be discovered by a practised anatomist; but they would disappear altogether if, instead of taking the most marked extremes of the type, the comparison were made between the intermediate and approximating varieties. Anomalies, produced accidentally, may be perpetuated artificially, and circumstances may produce the artificial state no less efficiently than design.

Such a result could hardly be produced arbitrarily in the human race, but it might be brought about by the force of circumstances. Dr. Pritchard has shewn that there is in all animals a tendency to the repetition of a variety which has once occurred; thus there are generally more albinos than one in the same family." Among the animals which exhibit varieties perfectly analogous to those of the human albinos, this tendency is very remarkable, particularly, with pets, such as cats, rabbits, and guinea-pigs.

Dr. Lord adds, "were a family in which any of these peculiarities had a tendency to occur, isolated from the general stock, so as to necessitate frequent intermarriage of its members, their peculiarities would be repeated, propagated, and in a few generations rendered permanent. [The female members of the noble family of Gordon have long been distinguished by a peculiar and beautiful formation of the neck and shoulder.] But this isolation could only take place when the world was thinly inhabited, and a wide space intervened between family and family. Any pecu

* Dr. Lord observes, "The existence of this tendency was strongly exemplified in the mare, which having once conceived by a quagga, had afterwards no less than three or four foals, begotten by different horses, yet all exhibiting more or less of the quagga form."

liarity occurring now-a-days speedily merges by intermixture, and returns to the common standard."

Medical statistics enable us to go farther, and shew that intermarriages of consanguinity have a tendency not only to perpetuate, but also to produce peculiarities; it is found that the greater number of children born with some natural deficiency, idiotic, blind, deaf and dumb, etc., are the issue of marriages between near relatives. Now, one of the commonest causes of monstrosity, as laid down by Halle, and since illustrated by Meckel, is what Doctor Lord calls "arrest of development;" that is, "the cessation of growth in any particular organ, while the rest advance towards their usual standard."

The Caucasian, the Mongolian, and the Negro, are the three primary or best marked varieties of the human species, and the difference appears strongest in the size and shape of the brain and its integument, the cranium. Let us now examine Dr. Lord's history of the brain, in his work on Popular Physiology. "The brain of man excels that of any other animal in complexity of organization and fulness of development. But this is only attained by slow and gradual steps. Examined at the earliest period that it is cognizable to the senses, it appears a simple fold of nervous matter, with difficulty distinguishable into three parts, while a little tail-like prolongation towards the hinder part is the only representation of a spinal marrow. Now, in this state it perfectly resembles the brain of an adult fish, thus assuming in transitu the form that in the fish is permanent. In a short time, however, the structure is become more complex, the parts more

distinct, the spinal marrow better marked-it is now the brain of a reptile. The change continues: by a singular motion certain parts (corpora quadrigemina) which had hitherto appeared on the upper surface, now pass towards the lower; the former is their permanent situation in fishes and reptiles, the latter in birds and mammalia. This is another advance in the scale, but more remains yet to be done. The complication of the organ increases-cavities termed ventricles are formed, which do not exist in fishes, reptiles, or birds; curiously organized parts, such as the corpora striata are added, it is now the brain of the mammalia. Its last and final change seems alone wanting, that which shall render it the brain of MAN."

"But we have not yet done with the human brain. M. Serres has made the still more singular observation, that in the advance toward the perfect brain of the Caucasian, or highest variety of the human species, this organ not only goes through the animal transmigrations we have mentioned; but successively represents the characters with which it is found in the Negro, Malay, American, and Mongolian nations. Nay further, the face partakes in these alterations. One of the earliest points in which ossification commences, is in the lower jaw. This bone is consequently sooner completed than the other bones of the head, and acquires a predominance, which, as is well known, it never loses in the Negro. During the soft pliant state of the bones of the skull, the oblong form which they naturally assume, approaches nearly the permanent shape of the American. At birth, the flattened face and broad smooth forehead of the infant, the position of the eyes

rather towards the side of the head, and the widened space between, represent the Mongolian form; while it is only as the child advances towards maturity that the oval face, the arched forehead, and the marked features of the true Caucasian become perfectly developed.

Arrest of development might take place--that is, the brain might cease to grow-from accidental pressure, from an impediment to the vessels carrying it nutrition, or from many other causes. If this arrest took place during any of the later phases we have described, man would be born with either the Negro or Mongolian cerebral formation. There is a tendency to produce such peculiarities in marriages of consanguinity, and there is no doubt that they would be perpetuated by family intermarriages.

"To the want of renovation," says Dr. Hancock, "I conceive we may chiefly attribute the barbarism which for unnumbered ages has reigned in Africa, and probably in the South-sea Islands, and amongst the aboriginal tribes of North America, and a jealousy of strangers has kept the Chinese stationary for many hundreds of years. The Arowahs and other American tribes roam at liberty through their native forests and savannahs, but, as it were by one universal magic spell or enchantment, they all kept most strictly to their respective tribes, and by such isolation, through a succession of ages, they have dwindled into pigmies, compared with those whose races are renovated and refreshed by inosculation, or grafting of other varieties."

The American and Negro types disappear by intermixture with the Caucasian. In the time of Herodotus, the Colchians had the black skin and curled hair of the