Tame Indians " at Bakia Blanca. 55 



of animated beings. This shows how nicely the 

 stimulus required to arouse hibernating animals is 

 governed by the usual climate of the district, and 

 not by the absolute heat. It is well known that 

 within the tropics, the hibernation, or more properly 

 aestivation, of animals, is determined, not by the 

 temperature, but by the times of drought. Near 

 Rio de Janeiro, I was at first surprised to observe, 

 that, a few days after some little depressions had 

 been filled with water, they were peopled by nu- 

 merous full-grown shells and beetles, which must 

 have been lying dormant. Humboldt has related 

 the strange accident of a hovel having been erected 

 over a spot where a young crocodile lay buried in the 

 hardened mud. He adds, ' The Indians often find 

 enormous boas, which they call Uji, or water ser- 

 pents, in the same lethargic state. To reanimate 

 them, they must be irritated or wetted with water.' " 

 While waiting for the Beagle at Bahia Blanca, 

 Darwin witnessed some of the incidents of a war 

 which was then in progress with the natives. The 

 troops of the famous South American dictator and 

 general, Rosas, had declared war against the In- 

 dians, and proposed to exterminate them if possible. 

 A report received, that a squad of men had been 

 murdered, occasioned no little excitement, and as 

 a result a troop of three hundred men came in from 

 the Colorado. They were not Spaniards, as Darwin 

 expected, but " tame Indians " of the tribe of the 

 Cacique Bernantio, and they afforded him as inter- 

 esting material for study and observation as so many 

 wild beasts. They were wild, reckless, even brutal, 



