276 



WALLACE ON SPECIES, 



[Ce. XXXV. 



want of pliilosopMcal caution. For lie cited experiments 

 wliich. were supposed to prove that the action of a voltaic pile 

 on a solution of potash could give origin to new species of 

 insects. The careless way in which these experiments had 

 been conducted contrasted in a striking 

 extreme caution displayed by those who he 



manner 



*om 



irvey's dictum that 

 The result of every 



micr 



the theory of spontaneous generation^ or at least to force the 

 abettors of the old doctrine to take refuge in the region of 



the 



minute. Distrust of the soundness of the 



author's judgment was also engendered by a suspicion that he 

 was not practically versed in the study of any one department 

 of natural knowledge. Every weak point, moreover, in this 

 treatise was exposed with unsparing severity by critics who 



im 



Lamarck's doctrine that Man 



the last link of a long series of progressive developments, but 

 had been connected by descent with the inferior animals. 

 Wallace on species. — The next important effort to determine 



manner in which new species may 



made in 1855 

 Natural History 



Mr. Alfred Wallace in the ^Annals of 



On the Law which 



New 



announced in this paper carried with them the authority of 



departments 



entomolo 



He 



explored during four years, conjointly with Mr. H. W. Bates, 

 the valley of the river Amazons, and the neighbouring equa- 

 torial parts of South America, their' expedition having been 

 expressly undertaken to collect facts *^ towards solving the 



'oblem 



Mr 



wards spent many years in studying the zoology of the Malay 

 Archipelago, devoting his attention especially to the birds 



and insects; and the result of his experience, aided by the 



information obtained 



summed 



t 



t 



i 



^ Series 2, vol, xvi. 



t Bates' Preface to his ' Naturalist on the Elver Aniazous.' 



