454 BIOLOGIC RELATIONS BETWEEN PLANTS AND ANTS. 



material and at the same time strengthening the structure) ; sometimes 

 they lodge in organs that x^rotect plants against herbivora (spines) or 

 against physical agencies (water reservoirs) ; finally, in certain cases, 

 the parasitic origin of the lodging organ seems unquestionable, it repre- 

 senting a real cecidium or gall. 



In certain types the ants seem to have adapted the lodging organ to 

 their own needs (by perforating the wall, by forming galleries) ; in others, 

 features at first abnormal, caused by the presence of ants, seem by 

 heredity and selection to have become normal, after which the insects 

 find lodgings ready for occupation without the necessity for preparatory 

 labor. 



Myrmecophilous features may, then, vary in their origin, according to 

 circumstances. 



The biologic relations between plants and ants thus tend, by insen- 

 sible degrees, to assume the complex, reciprocally advantageous condi- 

 tions of communal life; that is to say, of symbiosis. 



Looking at the phenomena of nature from the point of view of the 

 older naturalists, we should certainly go into raptures over the varied 

 means she employs to reach her ends. Were we to examine the relations 

 between plants and ants, as do those philosophers who seek final causes 

 for all biologic phenomena, we could not too much admire the prevision 

 of nature in putting within reach of those insects plants for their nour- 

 ishment, and in giving certain plants, in return for certain small advan- 

 tages granted, inhabitants capable of protecting them. 



But to our modern eyes the relations of living things, in the midst 

 of seemingly peaceful nature, appear in a somber light. Attack and 

 defense are their essential controlling conditions. Homo liomini lupus, 

 said the philosopher; and the race of man is no worse than other living 

 species in its struggle for existence. All beings. seem to have but two 

 aims : reproduction and destruction. Growth of the individual leads to 

 reproduction, indefinite multiplication of the species at the expense of 

 its neighbors, and the ruthless destruction of rivals. Does it not seem 

 as if each species was created for the extermination of some other, and 

 that soon the struggle of so many individuals of opposing tendencies 

 must result in the extinction of every living thing on the globe? 



But, strange to say, from this very contest arises accord ; the antago- 

 nism of living beings results in symbiosis; instability in equilibrium; 

 death in life. Chaos engenders order. The result of these tremendous 

 struggles, though usually inappreciable by the unsuspecting eye, may 

 be summed up in one word : harmony. A perfect accord is established 

 between creatures having nothing in common, precisely because of the 

 diversity of their needs; for in this accord the copartners have no inter- 

 est in despoiling their associates. 



Thus there is certainly confirmed, for life in general, the law of prog- 

 ress. Disregarding the sufferings and death of individuals, evolution 

 tends to establish between beings primitively rivals a modus vivendi 



