Method of Regulation in Behavior and in Other Fields. 491 



meet new conditions in a regulative way. A condition compar- 

 able to the establishment of a fixed reflex in behavior will result. 



It is perhaps more difficult to apply the method of regulation 

 above set forth to processes of growth and regeneration. Yet there 

 is no logical difficulty in the way. The only question would be 

 that of fact — whether the varied growth processes necessary do 

 primitively occur, under conditions that interfere with the physiolog- 

 ical processes. When a wound is made or an organ removed, is 

 the growth process which follows always of a certain stereotyped 

 character, or are there variations? It is, of course, well known 

 that the latter is often the case. In the regeneration of the earth- 

 worm, Morgan ('97) finds great variation; he says that in trying 

 many experiments, one finds that what ninety-nine worms cannot 

 do in the way of regeneration, the one hundredth can. The very 

 great variations in the results of operations on eggs and young 

 stages of animals is well known. Removal of an organ is known to 

 produce great disturbance of most of the processes in the organism, 

 and among others, in the process of growth. 



It appears then not impossible that in growth processes regula- 

 tion may be brought about in accordance with the same principles 

 as in behavior. A disturbance of the physiological processes 

 results in varied growth activities. Some of these relieve the 

 disturbance; the variations then cease, and these processes are 

 continued. In any given highly organized animal or plant the 

 different possibilities of growth will have become practically much 

 limited, and it is only from this limited number of possibilities 

 that selections can be made. In some cases, by the fixation of 

 .certain processes through the analogue of the law of the readier 

 resolution of physiological states, the organism or a certain part 

 thereof will have lost the power of responding to injury save in 

 one definite way. Under new conditions this one way may not 

 be regulatory, yet it may be the only response possible. This may 

 result in the formation under certain conditions of such things as 

 heteromorphic structures — a tail in place of a head, or the like, 

 from a part of the body that is accustomed (in normal develop- 

 ment) to produce such an organ. This would again correspond 

 to the production of a fixed reflex action in behavior, even under 

 circumstances where this action is not regulatory. 



It appears to the writer that the method of form regulation 

 recently developed in a most suggestive paper by Holmes ('04) 



