.^24 



ON THE VAUIETIES 



coloured pigment under particular circumstances that we not unfrequfentry. 

 see the skin of very fair women, when in astate of pregnancy, changed to^ 

 a deep tawny, and almost to a black ; and it is hence that the black pig- 

 ment of the eye is perpetually maintained and replenished.* 



Dr. Weils gave a paper to the Royal Society, which was read April I, 

 1813, containing an account of a woman, (Harriet Tresh) "whose left 

 shoulder, arm, and hand, are as black as the blackest African's, while all 

 the rest of the skin is very white. She is a native of Sussex, and the cause 

 she assigns is, that her mother set her foot upon a lobster during her preg- 

 nancy." So that we have not only instances of blacks being suddenly 

 bleached, but of whites being made more or less black. In like marmer, 

 confined birds, sometimes become wholly black ; and are said to become 

 so occasionally in the course of a single night. So the male kestral, from 

 being barred on the tail feathers, becomes wholly ash-coloured except at 

 the end; and the heron, gull, and others, whose tail is white when ma- 

 tured, are for the first two years mottled. 



IV. But it is probable that a very great part of the more striking dis- 

 tinctions we have noticed, and almost all the subordinate variations occa- 

 sionally to be met with, are the result of a mokbid and hereditary af- 

 fection. The vast influence which this recondite but active cause 

 possesses over both the body and the mind, are known in some degree to 

 every one from facts that are daily presenting themselves to us. We see 

 gout, consumption, scrophula, leprosy, propagated on various occasions, 

 and madness, and fatuity, and hypochondriacal affections as frequently. 

 Hence the unhappy race of Albinoes ; and whole pedigrees of white ne- 

 groes ; hence the pigmy stature of some families, and the gigantic size of 

 others. 



Even when accident, or a cause we cannot discover, has produced a 

 preternatural conformation or defect in a particular organ, it is astonishing 

 to behold how readily it is often copied by the generative principle, and 

 how tenaciously it adheres to the future lineage. A preternatural defect of 

 the hand or foot has been propagated for many generations, and has in 

 numerous instances laid a foundation for the family name. The names 

 of Varus and Plautus among the ancient Romans afford famihar exempli- 

 fications. Hence, hornless sheep and hornless oxen produce an equally 

 hornless offspring : the broad-tailed Asiatic sheep yields a progeny with a 

 tail equally monstrous, and often of not less than half a hundred pounds' 

 weight ; and dogs and cats with mutilated tails not unfrequently propagate 

 the casual deficiency. 



There is a very peculiar variety of the sheep kind given in the Philo- 

 sophical Transactions for 1813, by Colonel Humphreys of America, and! 

 which the American naturahsts have called, from its bowed or elbowy legs, 

 ovis Ancon: but the common people " the otter breed" from its resem- 

 blance to the general form of the otter, and a rumour that it was at first 

 produced by an unnatural intercourse between individuals of the two dis- 

 tinct kinds. Its size is small ; the full weight being about 45lb. with loose 

 articulations, crooked fore-legs, and great feebleness of power ; whence it 

 walks with difficulty, and is therefore quiet and not fond of rambhng. 

 Accident seems to have produced this kind first, but the form has been 

 most correctly preserved in the progeny ; and so tenaciously, that if a 

 (gomraon sheep and ancon sheep of either sex unite, the young will be 



I * Camper's Lect. on Comp. Anat. in regard to the Art of Drawing, 



