I] OF ADAPTATION AND FITNESS 3 



construction, for instance in the honeycomb, he would fain refer it 

 to psychical instinct, or to skill and ingenuity, rather than to the 

 operation of physical forces or mathematical laws; when he sees in 

 snail, or nautilus, or tiny foraminiferal or radiolarian shell a close 

 approach to sphere or spiral, he is prone of old habit to believe that 

 after all it is something more than a spiral or a sphere, and that in 

 this "something more" there lies what neither mathematics nor 

 physics can explain. In short, he is deeply reluctant to compare 

 the living with the dead, or to explain by geometry or by mechanics 

 thp things which have their part in the mystery of life. Moreover 

 he IS httle inclined to feel the need of such explanations, or of such 

 extension of his field of thought. He is not without some justifi- 

 cation if he feels that in admiration of nature's handiwork he has 

 an horizon open before his eyes as wide as any man requires. He 

 has the help of many fascinating theories within the bounds of his 

 own science, which, though a little lacking in precision, serve the 

 purpose of ordering his thoughts and of suggesting new objects of 

 enquiry. His art of classification becomes an endless search after 

 the blood-relationships of things living and the pedigrees of things 

 dead and gone. The facts of embryology record for him (as Wolff, 

 von Baer and Fritz Miiller proclaimed) not only the life-history of 

 the individual but the ancient annals of its race. The facts of 

 geographical distribution or even of the migration of birds lead on 

 and on to speculations regarding lost continents, sunken islands, or 

 bridges across ancient seas. Every nesting bird, every ant-hill or 

 spider's web, displays its psychological problenis of instinct or intel- 

 ligence. Above all, in things both great and small, the naturajist 

 is rightfully impressed and finally engrossed by the peculiar beauty 

 which is manifested in apparent fitness or "adaptation" — the flower 

 for the bee, the berry for the bird. 



Some lofty concepts, like space and number, involve truths remote 

 from the category of causation; and here we must be content, as 

 Aristotle says, if the mere facts be known*. But natural history 

 deals with ephemeral and accidental, not eternal nor universal 



* ovK diraiTrjTeop 5 ov8i ttju airiav ofxoiojs, dW LKavou ^v tlctl rb on deLxdrjvai /caXcDj 

 Eth. Nic. 1098a, 33. Teleologist as he was at heart, Aristotle realised that mathematics 

 was on another plane to teleology: rds 5^ fxad-qfiariKas oOdeva iroieladai \6you wepi 

 dyaduv xat KaKQv. Met. 996a, 35. 



