244 THE POPULAR SCIENCE MONTHLY. 



ocean. Such seeds again find lodgment among the broken corals, and 

 among the decaying pumice. Under tropical heat and moisture, they 

 soon spring to life. The moment a palm-tree rears its fronds, it is 

 visited by birds — especially by fruit-eating pigeons — bringing with 

 them other seeds, which are deposited with convenient guano. These 

 in turn take root and live. Each new accession to the incipient forest 

 attracts more and more numerous winged messengers from intermi- 

 nable archipelagoes, until the result is attained which so excites our ad- 

 miration and our wonder, in the atoll-islands of the Pacific. All this 

 is simple. But here as elsewhere it is the first step that costs. Are 

 all atolls nothing more than the cup-like rings of volcanic vents ? And 

 if they are, can a like explanation be given for the barrier-reefs which 

 lie off continental coasts, and Avhere the crater-like lagoon of an atoll 

 is represented only by a vast linear expanse of included and protected 

 sea ? 



Here were problems eminently attractive to such a mind as that 

 of Darwin. Vast in the regions they affect, complicated in the results 

 which are presented, most beautiful and most valuable to man in the 

 products which are concerned, the facts do nevertheless suggest some 

 physical cause which would be simple if only it could be discovered. 

 All his faculties were set to work. Analysis must begin every work 

 of reason. Its function is to destroy — to pull to pieces. Darwin 

 had to deal with some theories already formed. With some of these 

 he had no difficulty. " The earlier voyagers fancied that the coral- 

 building animals instinctively built up these great circles to afford 

 themselves protection in the inner parts." To this Darwin's answer 

 was complete. So far is this explanation from being true, that it is 

 founded on an assumption which is the reverse of the truth. These 

 massive kinds of coral which build up reefs, so far from wanting the 

 shelter of a lagoon, are unable to live within it. They can only live 

 and thrive fronting the open ocean, and in the highly aerated foam of 

 its resisted billows. Moreover, on this view, many species of distinct 

 genera and families are supposed instinctively to combine for one 

 end ; and of such a combination Darwin declares " not a single in- 

 stance can be found in the whole of Nature." This is rather a sweej)- 

 ing assertion. In the sense in which Darwin meant it, and in the 

 case to which he applied it, the assertion is probably, if not certainly, 

 true. The weapon of analysis, however, if employed upon it, would 

 limit and curtail it much. We can not, indeed, suppose that any of 

 the lower animals, even those much higher than the coral-builders, 

 have any consciousness of the ends or purposes which they or their 

 work subserve in the great plan of Nature. But Darwin has himself 

 shown us, in later years, how all their toil is co-operant to ends, and 

 how not only different species and families, but creatures belonging 

 to different kingdoms, work together most directly, however uncon- 

 sciously, to results on which their common life and propagation abso- 





