MAN. 



tamed individuals. The domesticated 

 animals become liable to produce mon- 

 strous fetuses, and are exposed to new 

 and numerous diseases : their bodies are 

 even invaded by new kinds of worms, of 

 which the hydatids in swine, forming" 

 what is commonly called the measles, are 

 an indubitable instance. 



The three causes now mentioned pro- 

 duce their effect in changing the original 

 character of the animal, and giving origin 

 to a variety, only after a great length of 

 time, and a continued action through se- 

 veral generations. But these changes 

 are communicated much more quickly by 

 the process of generation. When two 

 varieties copulate together, the offspring 

 resembles neither parent wholly, but par- 

 takes of the form and other peculiarities 

 of both. This cannot with propriety be 

 termed hybrid generation; as authors 

 apply that expression to the x produce of 

 the copulation of different species, as of 

 the horse and ass, &c. In this sense hy- 

 brids are never produced in the human 

 species : for although we read various in- 

 stances of men and women having com- 

 merce with animals, there is not a shadow 

 of reason for supposing that such copu- 

 lations ever produced an offspring. Breed- 

 ing from different varieties has a great 

 effect in changing the colour and form of 

 the animal produced; and hence this 

 method of improving and ennobling the 

 race is practised with great effect in the 

 domestic animals, particularly the horse 

 and sheep. 



It seems even possible that a disposi- 

 tion originally morbid may be transmitted 

 by generation, and acquire a permanent 

 character. The peculiar whiteness of 

 the skin, with red colour of the eye, oc- 

 curring in the rabbit and ferret, and va- 

 rious other animals, as well as in the Al- 

 bino of the human race, appears in v the 

 first instance to be P> morbid affection of 

 the body ; and when it occurs in one or 

 two instances only, in the human subject, 

 has the appearance of a leprous cachexy. 

 But, in the animals just mentioned, all 

 the unnatural characters have been lost, 

 and it is established as a permanent va- 

 riety. We have, moreover, many facts, 

 shewing that, in some cases, cr.su al muti- 

 lations are transmitted to the offspring : 

 as want of tail in a cat or dog. (Philoso- 

 phical Magazine, vol. iv. p. 2. Ander- 

 son's Recreations, vol. i. p. 69.) The 

 Jews are frequently born with so little 

 foreskin, that it is hardly possible to cir- 

 cumcise them : this they call being born 

 circumcised. (Philosophical Magazine, 

 vol. iv. p. 5.) 



In applying the reasonings derived from 

 the causes just mentioned, it may not be 

 amiss to advert to the following rules : 

 1. The greater the number of causes of 

 degeneration, and the longer they con- 

 tinue to act on the same species, the 

 more obviously will that species deviate 

 from its original formation. Man, there- 

 fore, must be expected to vary more than 

 any animal, since he has been subjected 

 from his very origin to the united agen- 

 cies of climate, food, and way of life. 2. 

 A cause, possessing in itself sufficient effi- 

 cacy, may be weakened by the concur- 

 rence of other conditions, tending to 

 diminish its operations. Thus, countries 

 placed under the same parallel of latitude 

 have very different temperatures; and 

 the effects of situation on the human 

 subject are varied, according as it is more 

 or less elevated, or as it may be influenced 

 by the neighbourhood of the sea, marshes, 

 mountains, or woods, &c. 3. The source 

 of degeneration is often to be sought for, 

 not in any immediate cause, but in the 

 mediate influence of some more latent 

 agency. Thus, the dark colour of the 

 skin may not arise from the direct action 

 of the sun, but from its more remote, but 

 very signal, influence on the hepatic sys- 

 tem. 4. These indirect and mediate 

 causes may be so very obscure, that we 

 cannot form even any probable conjecture 

 as to their nature ; yet we seem to be 

 warranted in referring those phenomena 

 of degeneration, which hitherto appear 

 enigmatical, to the operation of such un- 

 known powers. Thus we must explain 

 the constant national forms of crania, 

 colours of the eye, &c. 



YAIUETIES OF THE HtJMAX RACE. 



The colour of the skin forms a very con- 

 stant hereditary character, most clearly 

 influenced by that of both parents in the 

 hybrid offspring of different varieties, 

 having a close and nearly uniform relation 

 to that of the hair and iris, and indeed to 

 the whole temperament of the individual ; 

 and for all these reasons attracting most 

 immediately the attention of the cursory 

 observer. 



The seat of this colour is in a thin mu- 

 cous stratum, interposed between the 

 cuticle, or dead surface of the body, and 

 the true skin, and called rete mucosum, 

 or rete Malpighii. The native reddish 

 white of the real skin appears through 

 this, which is very thin and almost colour- 

 less, in the white races of mankind. But 

 in the darker varieties the rete mucosum 

 is much thicker, and contains throughout 



