FITNESS AND ADAPTATION 69 



with, and cooperative response to the world at large; 

 and still endure. These methods are measurable only 

 in the sum total of organic services rightly performed. 



The yeast cell is no doubt an extraordinarily com- 

 plex system in miniature. It produces something like 

 a score of different enzymes, or about all of these re- 

 markable substances known to science, and some of 

 these enzymes have a profound influence, for good and 

 evil, on the social life of man. But the yeast does not 

 appear to profit directly, or in due proportion, from 

 its own products. It has no neuro-muscular mecha- 

 nism, like that of animals, by which it can move about, 

 or respond to its environments ; and yet it is more widely 

 distributed over the earth's surface than any of the 

 higher plants or animals. 



On the other hand, the orchid is a much larger, and 

 on the whole, a much more elaborately constructed 

 plant. Its methods of fertilization have long been the 

 stock examples of cooperative fitness and adaptation 

 for special purposes; and yet the orchids are not espe- 

 cially abundant, nor widely distributed, nor vigorous 

 plants, nor very serviceable agents to life at large. The 

 brilliant and varied colors of its flowers, their bizarre 

 shapes, their perfumes and nectars which lure the "buc- 

 caneering bee," or some other unwilling agent, to con- 

 cealed traps and time-set springs, finally letting him 

 go his way, besmeared and bepollened in the service 

 of the plant, are indeed marvels of adaptation. And 

 yet the humble potato gets the same service performed, 

 at least as efficiently, if not in such a flamboyant manner. 



Thus the fitness and adaptation of the yeast plant, 

 potato, and orchid, are not measured by the construc- 

 tive and saving services performed for themselves 



