BIOLOGICAL INTRODUCTION 19 



working capacity of the machine, but gives little insight into 

 the real value of the work done. In the second place, life may 

 be measured in terms of the extensity or number and diversity 

 of environmental relations. This takes account of the range 

 or working distance of the organization and, in general, of the 

 efficiency of the work done. For evidently the organism which 

 has few and simple relations with the environment, so that it 

 can adjust itself to only a small range of external conditions, 

 is less efficient than one which has many diverse relationships 

 and an extensive series of possible adjustments, even though the 

 actual amount of energy expended may be vastly greater in the 

 former than in the latter case. The first of these standards is a 

 tolerably satisfactory measure of the vegetative functions of 

 the body, sometimes less happily termed the "organic functions." 

 We have no word in common use which covers precisely the 

 group of activities embraced by our second standard of meas- 

 urement, though the terms "animal functions," "somatic or 

 exteroceptive activities" are sometimes used in about this 

 sense. 



Let us now endeavor to illustrate the last topic a little more 

 concretely. We are standing on a hilltop overlooking a 

 meadow, through which runs a mountain brook, and beyond 

 the valley is another range of rugged hills. In the fence-corner 

 near us is a patch of daisies and clover with a honey-bee buzzing 

 from flower to flower. A plowboy is crossing the field, and at 

 our elbow an artistic friend is busy with sketching pad and 

 brushes. Here are four things which have this at least in 

 common, that they are alive daisy, bee, plowboy, artist. 

 There can be no doubt about their vitality, but how differently 

 they respond to the sunshine, the rain, and the other forces of 

 nature. 



The daisy expands in the vivifying light of the summer sun, 

 the energy of whose actinic rays is used to build up living proto- 

 plasm and vegetable fiber from the inert substances of air and 

 soil. Its vitality, measured in terms of energy transforma- 

 tion, is great; yet how limited its range of life, how helpless -in 

 the face of the storms of adversity which are sure to buffet it. 

 Rooted to its station, it can only assimilate what food is brought 

 to it and it cannot flee from scorching wind or blighting frost. 



