MODERN BIOLOGY 463 



In his youth Danvin was a confirmed lover of the open-air life; a good 

 shot, an enthusiastic huntsman, and a keen observer of life in nature. This 

 love of animate life in the open air he retained even in his old age; long 

 after ill health had compelled him to give up shooting and voyages of ex- 

 ploration, he applied himself with indefatigable devotion to the care and 

 observation of life in his park and garden. Dogs and cats, birds, insects, and 

 earthworms, no less than plants of the most varied kinds, were to him a 

 never-wearying source of joy and observation; all their manifestations of 

 life in the minutest detail were the object of his most careful study; animals' 

 actions, instincts, and manifestations of intelligence were observed, analysed, 

 and summarized by him day by day and year by year with never-failing in- 

 terest. His theoretical training, on the other hand, was deficient — -most thor- 

 ough in the sphere of geology, whereas in biology it was, on the whole, 

 limited to the systematic side. His observations made during the circum- 

 navigation of the world also bear witness to this restricted basis on which 

 his education was founded. He was, moreover, in his youth a firm believer 

 in the Christian faith — he intended, in fact, to become a clergyman — and he 

 accepted without criticism the traditional dogmas, including, of course, the 

 doctrine of the origin of living species as the result of a divine act of crea- 

 tion. During his voyage, however, he found that this belief conflicted with 

 the results of his observations. His diary contains many proofs of this; in 

 particular, the existence of many species with a small area of distribution, 

 of forms closely allied to one another, but not alike, and taking the place 

 of one another in different localities, yet not existing together, seemed to 

 him difficult to reconcile with "nature's great plan." Why had it been neces- 

 sary to create all these slightly differentiated and narrowly distributed spe- 

 cies? He spent one month on the desolate Galapagos Islands, situated a long 

 way off the coast of South America and composed of volcanic lava compara- 

 tively recently cast up out of the ocean; here he felt himself "placed in prox- 

 imity to the very act of creation itself." But here he found a fauna of markedly 

 South American genera, though possessing peculiar species; of many birds 

 each separate island had its own species. That one species should have been 

 created for each small island seemed to him irrational; but how, then, had 

 the different species arisen and why did they belong to the South American 

 genera? This problem, having once penetrated his mind, gave him no rest. 

 Upon his return home he at once started to record in a separate book his 

 experiences in connexion with the question of the formation of species, and 

 he sought long and restlessly for proofs of the correctness of his ideas. In 

 1844 he writes in a letter to his friend the botanist Hooker: "I have read 

 heaps of agricultural and horticultural books and have never ceased col- 

 lecting facts. At last gleams of light have come, and I am almost convinced 

 (quite contrary to the opinion I started with) that species are not (it is like 



