5i8 THE WONDER OF LIFE 



Finally, in thinking over this difficult problem of adapta- 

 tions, we must remember the importance of the active 

 organism itself. As Professor James Ward has well pointed 

 out, it may seek out and even in part make its environment ; 

 it is not only selected, it selects ; it acts as well as reacts. 

 And although the details and finesse of this may have been 

 elaborated in the course of selection, the primary poten- 

 tiality of it is an essential part of the secret of that kind 

 of activity which we call Life. 



Illustrations of Adaptations. The structure of a long 

 bone in a mammal is adapted to give the utmost firmness 

 with the minimum expenditure of material ; the unique 

 pollen-basket on the hind legs of worker-bees is adapted 

 to stow away the pollen ; the colours and patterns on the 

 wings of leaf-insects are adapted to harmonize with the 

 foliage on which they settle ; the parts of flowers are often 

 adapted to ensure that the insect- visitors are dusted with 

 pollen, and thus to secure cross-fertilization ; the peacock 

 is adapted to captivate the pea-hen ; the mother mammal 

 is adapted for the prolonged pre-natal life of the young ; 

 the so-called ' egg-tooth ' at the end of a young bird's bill 

 is adapted to the single operation of breaking the egg-shell 

 and so on throughout the whole of the animate world. It 

 is indeed a mistake to dwell upon signal instances of adapta- 

 tions, since (apart from degenerative changes in old age, 

 morbid processes, perverted instincts, rudimentary or 

 vestigial structures, and certain ' indifferent ' characters 

 which are not known to have any vital significance) almost 

 every detail of structure and function may be regarded as 

 adaptive. 



The Mole. In illustration of adaptive characters let 

 us consider a common animal like the mole, ' the little 



