164 SYMBIOSIS 



Here, owing to special circumstances, the birds have proved 

 themselves so useful as seed carriers to certain shrubs and trees, 

 that they have actually been able to determine the island flora 

 in a manner more useful to themselves than to mammals, which, 

 for several reasons, are here very sparse. This isolated 

 phenomenon, however, by no means disproves the fact that, 

 generally speaking, the mammalia (including man) as the higher 

 order and representing higher values, are pre-eminent in deter- 

 mining the flora of our globe. 



Views similar to the co-operative interpretation of evolution 

 for which I have now for some years contended, have recently 

 been advanced by Mr. E. Kay Robinson, well known as the 

 Editor of "Country-Side," "Country-Side Leaflet," etc., as the 

 following quotations will show : 



Most people (says Mr. Kay Robinson) would thoughtlessly regard 

 animals and birds which eat fruits, berries, and seeds, as the enemies of the 

 plants which produce them, and especially would they regard the grazing 

 animal as the enemy of the grass. Yet they would be wrong in every case. 

 The immense genus of trees to which the apple, pear, etc., belong, un- 

 doubtedly owe their world-wide dominance to the habit of fruit-eating 

 animals, which devour the pulp and throw away the core, or drop the 

 seeds. In an English countryside you can locate the site of an ancient 

 orchard by the prevalence of wild crab-apple trees in the hedges, all sown 

 in this way. Similarly the mountain ash would still be confined to the 

 distant valley where it originated, but for the aid of wide-ranging berry 

 eating birds, which have distributed it broadcast in all the upland valleys 

 of the temperate zone. When the seeds themselves, rather than berries 

 or fruits, are eaten, the reciprocity of interest is less direct and definite ; 

 but birds can only eat the seeds of a given plant during the short time 

 of its harvest, and during the rest of the year they help the plants by 

 killing insects, and even during the seed-harvest they do much good by 

 scattering the residue of seed which they do not devour or cannot digest. 

 For in all these cases of mutual assistance the animal (a term which, of 

 course, includes " bird ") is sustained by food which the plants produce 

 in excess of their own requirements, and in almost all cases the animal 

 also destroys insects, etc., which are injurious to the plants. The result 

 is that the allies prosper side by side ; while carnivorous animals, which 

 live by destruction, are always making their environment worse for them- 

 selves, and inevitably tend towards extinction. 



Mr. Kay Robinson thinks the case of the grass and the grazing 

 animal a particularly striking example of mutual aid. This is 

 what he says : 



In grazing, the animal eats down everything to within half-an-inch, 

 say of the ground. This is fatal to the seedlings of all large plants, as 

 well as to most small plants all, that is, except a few which have some 



