140 ANIMAL INTELLIGENCE. 



however, that these and all the above observations, being 

 independently made and separately recorded, serve to cor- 

 roborate one another so strongly that we can entertain no 

 reasonable doubt concerning the wonderful facts which 

 they convey. 



I shall now bring these numerous instances to a close 

 with a quotation from Mr. Belt, which reveals in the most 

 unequivocal manner surprising powers of observation and 

 rational action on the part of the leaf-cutting ants of 

 South America, whose general habits we have already con- 

 sidered : 



A nest was made near one of our tramways, and to get to 

 the trees the ants had to cross the rails, over which the waggons 

 were continually passing and repassing. Every time they came 

 along a number of ants were crushed to death. They perse- 

 vered in crossing for some time, but at last set to work and 

 tunnelled underneath each rail. One day, when the waggons 

 were not running, I stopped up the tunnels with stones ; but 

 although great numbers carrying leaves were thus cut off from 

 the nest, they would not cross the rails, but set to work making 

 fresh tunnels underneath them. 



Anatomy and Physiology of Nerve-centres and 

 Sense-organs. 



The foregoing facts concerning the intelligence of 

 ants fully justifies Mr. Darwin's observation that * the 

 brain of an ant is one of the most marvellous atoms of 

 matter in the world, perhaps more so than the brain of a 

 man.' It may therefore be interesting in this particular 

 case to depart from the lines otherwise laid down through- 

 out the present work, and to devote a short section to the 

 anatomy and physiology of this nerve-centre with its ap- 

 pended organs of sense. 



The brain of an ant, then, is proportionally larger than 

 that of any other insect. (See Titus Grraber, ' Insects,' vol. 

 i. p. 255.) In structure, also, the brain of an ant is in 

 advance of that of other insects, its nearest analogue being 

 the brain of a bee. The superiority of development is 

 particularly remarkable with reference to the * stalked 

 bodies ' of Dujardin ; and these are largest in neuter 



