36 ENTOMOLOGICAL NEWS [Jan., '14 



istence was intensified, and again to use Darwin's expression 

 "haunted" us. 



Finally, both Darwin and myself, at the critical period when our 

 minds were freshly stored with a considerable body of personal ob- 

 servation and reflection bearing upon the problem to be solved, had 

 our attention directed to the system of positive checks as expounded 

 by Malthus in his "Principles of Population." The effect of this was 

 analogous to that of friction upon the specially-prepared match, pro- 

 ducing that flash of insight which led us immediately to the simple but 

 universal law of the "survival of the fittest," as the long sought effec- 

 tive cause of the continuous modification and adaptation of living 

 things. 



Wallace's interest in beetles, as he tells in My Life (i, pp. 

 236-237), was due to his meeting Henry Walter Bates, in 1844 

 or 1845, as a result of which he not only began to collect these 

 insects but also to enter into a correspondence with Bates that 

 eventually led to their joint visit to the Amazon. Their choice 

 of this region of the world was the result of reading W. H. 

 Edwards' A Voyage up the Amazon, published in 1847. Ed- 

 wards, being in London soon after, gave the young Englishmen 

 letters of introduction to friends at Para. Forty years later, 

 in April, 1887, Wallace renewed his personal acquaintance with 

 the great American lepidopterist by a visit to the latter's home 

 at Coalburgh, West Virginia. 



The richest parts of Wallace's South American collections, 

 1848-1852, were lost by the burning of the vessel on which he 

 was returning to England. He mentions, in his Narrative of 

 Travels on the Amazon and Rio Negro, having gathered goo 

 species of diurnal Lepidoptera. 



He was more successful in his journey to the East, 1854- 

 1862, and, in the preface to The Malay Archipelago, tells us 

 that when he returned to England in the spring of 1862 he 

 found that the collections which he had retained for his private 

 use included "at least twenty thousand beetles and butterflies, 

 of about seven thousand species," while the total numbers of 

 specimens which he secured were 13100 specimens of 

 Lepidoptera, 83200 Coleoptera and 13400 other insects. 

 His papers, The Malayan Papilionidae, as illustrating the 

 Theory of Natural Selection (Trans. Linn. Soc. Lond. xxv), 



