FUNCTIONS OF THE BRAIN. 95 



are both equally below those of the Negro. The gradation 

 of organization and of mind passes through the monkey, 

 dog, elephant, horse, to other quadrupeds ; thence to birds, 

 reptiles, and fishes ; and so on to the lowest links of the 

 animal chain. 



In ascending these steps of one ladder, following in regu- 

 lar succession at equal intervals, where shall we find the 

 boundary of unassisted organization ? where place the be- 

 ginning of the immaterial adjunct ? In tliat view which 

 assimilates the functions of the brain to those of other orga- 

 nic parts, this case has no difficulty. As tlie structure of 

 the brain is more exquisite, perfect, and complex, its func- 

 tions ought to be proportionally so. It is no slight proof of 

 the doctrine now enforced, that the fact is actually thus ; 

 that the mental powers of brutes, as far as we can see, are 

 proportional to their organization. 



We cannot deny to animals all participation in rational 

 endowments, without shutting our eyes to the most obvious 

 facts — to indications of reasoning, which the unprejudiced 

 observation of mankind has not failed to recognize and ap- 

 preciate. Without adverting to the well-known instances 

 of comparison, judgment, and sagacity, in the elephant, the 

 dog, and many other animals, let us read the character 

 drawn by Humboldt of the South American mules. 



" When the mules feel tliemselves in danger they stop, 

 turning their heads to the right and to the left : the motion 

 of their ears seems to indicate tliat they reflect on the deci- 

 sion they ought to take. Their resolution is slow, but al- 

 ways just, if it be free ; that is to say, if it be not crossed 

 nor hastened by the imprudence of the traveller. It is on 

 the frightful roads of the Andes, during journeys of six or 

 seven months across mountains furrowed by torrents, that 

 the intelligence of horses and beasts of burden displays itself 

 in an astonishing manner. Thus the mountaineers are 

 heard to say, * I will not give you the mule whose step is 

 the easiest, but him who reasons best*.' " 



* Personal Narrative v. iii. 



