i4 The Study of Animal Life PART i 



and even the parts of the flower sepals, petals, stamens, 



and carpels, are in reality all leaves or appendages more 



or less modified for diverse work. The mouth-parts of a 



lobster are masticating legs, and a bird's wing is a modified 



arm. The old naturalists were so far right in insisting on 



i\ the fact of a few great types. Nature, Lamarck said, is 



\\ never brusque ; nor is she inventive so much as adaptive. 



4. Wealth of Numbers. Large numbers are so unthink- 

 able, and accuracy in census-taking is so difficult, that we 

 need say little as to the number of different animals. The 

 census includes far over a million living species a total so 

 vast that, so far as our power of realising it is concerned, 

 'it is hardly affected when we admit that more than half 

 are insects. To these recorded myriads, moreover, many 

 newly-discovered forms are added every year now by the 

 individual workers who with fresh eye or improved micro- 

 scope find in wayside pond or shore pool some new thing, 

 or again by great enterprises like the Challenger expedition. 

 Exploring naturalists like Wallace and Semper return from 

 tropical countries enriched with new animals from the dense 

 forests or warm seas. Zoological Stations, notably that of 

 Naples, are "register -houses" for the fauna of the neigh- 

 bouring sea, not merely as to number and form, but in 

 many cases taking account of life and history as well. Nor 

 can we forget the stupendous roll of the extinct, to which 

 the zoological historians continue to add as they disentomb 

 primitive mammals, toothed birds, giant reptiles, huge 

 amphibians, armoured fishes, gigantic cuttles, and a vast 

 multitude of strange forms, the like of which no longer 

 live. The length of the Zoological Record, in which the 

 literature and discoveries of each year are chronicled, the 

 portentous size of a volume which professes to discuss with 

 some completeness even a single sub-class, the number of 

 special departments into which the science of zoology is 

 divided, suggest the vast wealth of numbers at first sight so 

 bewildering. More than two thousand years ago Aristotle 

 recorded a total of about 500 forms, but more new species may 

 be described in a single volume of the Challenger Reports. 

 We speak about the number of the stars, yet more than one 



