22 NATURAL SCIENCE. Jan., 



4. The colour of Darwin's picture of nature certainly suggests a 

 very keen and continuous struggle for existence. He speaks of ' the 

 battle for life ' and ' the severe often recurrent struggle,' and he ex- 

 presses recoil from a world which is so full of misery. " In a state of 

 nature, animals and plants have to struggle from the hour of their 

 birth to that of their death for existence." Mr. Wallace uses similar 

 expressions. (See " Origin of Species" and " Darwinism.") 



5. But it must be observed that Darwin used many saving clauses, 

 of which one of the most important is : — " I should premise that I use 

 this term [struggle for existence] in a large and metaphorical sense 

 including dependence of one being on another, and including (which 

 is more important) not only the life of the individual, but success 

 in leaving progeny." (" Origin of Species," p. 50.) Similarly, 

 Mr. Wallace says: "the struggle for existence, under which all 

 animals and plants have been developed, is intermittent and exceed- 

 ingly irregular in its incidence and severity." ("Darwinism," p. 139.) 



6. Since we wish to know, not so much what even the masters 



have said, but what is actually the case, it would not be of special 



importance to consider individual statements, were it not that the 



opinions of the experts are presumably summations of cumulative 



evidence, wider than their works supply. Thus the generalisation 



that the struggle is most severe between closely-allied forms can hardly 



be supposed to rest on Darwin's half-dozen examples, not all of 



which are correct. In fact, having relatively few actual statistics of 



elimination except in cases, such as bison and beaver, where man has 



been the discreditable chief agent, we must still depend largely on the 



impressions of those who have had wide experience. Nor can it be 



denied that the conception of the struggle for existence has derived its 



force, not wholly from actual observation of what occurs, but very 



largely from inference as to what, it is believed, must occur. The 



necessity for its occurrence depends upon (a) the tendency of organisms 



to rapid increase, (b) the variability of the physical environment, tc 



which organisms are at best only relatively well adapted, and (c) 



the secondary consequences of these primary facts. 



7. Indecision of statement in regard to the stringency of the 

 struggle is inevitable, being due in part to the complexity of nature, 

 in part to the (alleged) fact that 'egoism' is continually moderated by 

 ' altruism,' in part to the fact that the conception is based partly on 

 observation and partly on inference. It is plain that the nature of the 

 struggle must vary with the nature of the organism, thus that of the 

 beech tree must be very difterent from that of the squirrel. It is plain 

 that the phrase includes three forms of struggle — with related fellows, 

 with foes, and with physical nature ; therefore, the reality must be very 

 diverse. The objects of competition include (i) continued individual 

 existence and enjoyment, and (2) the continuance of family and race, 

 both objects of manifold complexity. Finally, the struggle varies with 

 the rate of reproduction and the variability of the environment. In 



