OF THE CLASS MAMMALIA. 255 



fear may afterwards be superadded ; but this must be done 

 with great caution, lest it excite terror and disgust. 



But all mammals do not thus readily lay aside their savage 

 disposition, being either less confiding or less sensible to acts 

 of kindness, or it may be that their intellect is lower ; but 

 be this as it may, it is evident that any animal, to become 

 completely domesticated, must be disposed to it by the instinct 

 of sociability. No solitary mammal ever becomes completely 

 domesticated, however readily he may be tamed.* Sociability 

 is an essential of complete domesticity, man becoming, as it 

 were, the head of the troupe. A disposition to domesticity 

 may be considered as the extreme development of the instinct 

 of sociability, f 



408. Let us now consider the moral and physical influ- 

 ences which domesticity exercises over the domestic races of 

 animals ; how, in fact, it produces new varieties. 



The physiological law of hereditary resemblances holds 

 true in all animals, man included ; the young resemble their 

 parents in conformation, physical and mental qualities, and 

 even in respect of disease itself. But all the individuals of a 

 race do not possess in the same degree the same qualities, 

 moral and physical; and hence arises the possibility of giving 

 to certain qualities a higher and more constant development. 

 Within certain limits, then, man may modify races, by regu- 

 lating the succession of generations, selecting a type or 

 standard for the new variety he is desirous of creating. J By 

 endeavouring thus to develop from generation to generation 

 a certain physical or mental quality, we render such qualities 

 hereditary, at least for a time. 



* The cat may seem an exception to this view, but, in fact, the cat is never 

 completely domesticated. 



t The theory of domestication is one of extreme difficulty. E. K. 



j The bloodhounds transplanted into America by the Spaniards, employed 

 at first to pursue only men and deer, furnish a remarkable instance of the 

 power of transmitting certain newly-created mental quali ties, hereditarily. 

 In different parts of America, as on the central table-land of Santa-Fe, these 

 animals have preserved their original instincts and physical qualities, but 

 amongst the poor inhabitants of the banks of the Magdalena they have become 

 degraded, partly by a mixture with other dogs, partly by a scarcity of food, 

 and in this degenerate race of the bloodhound a new instinct has been 

 developed. The chase in which they have been long emj loyed is that of the 

 white-muzzled Peccari. The skill of the dog consists in moderating its 

 courage or ardour, so as not to attack any individual of the troop or herd of 

 peccaris, but to keep the whole in check. IS'ow it has been observed that 

 these dogs act thus on the very first occasion they hunt the peccari, whereas 

 any strange dog throws himself on them at once, and is devoured in an 

 instant, whatever be its strength. 



