192 SCIENCE AND PHILOSOPHY OF THE ORGANISM 



establishment of irritability after stimulation has occurred, 

 or, in certain other cases, the fact that in spite of permanent 

 stimulation irritability seems to exist permanently also, 

 physical analogies or even explanations might very well 

 be found. 1 



If now we ask whether there is anything like an adapta- 

 tion appearing in the general characteristics of irritation 

 and irritability, it seems to me that we may answer the 

 question in an affirmative manner, as far as primary regula- 

 tion comes into account. We, certainly, have not studied 

 any abnormal regulatory lines of general functioning, we 

 only have studied general functioning itself; but, indeed, 

 there was a certain sort of regulation in functioning. Of 

 course, by showing that one of the most general features of 

 all functioning is primary-regulatory in itself, we do not 

 deny the possibility of many specific functions in which 

 real secondary regulations actually do exist. Nothing 

 indeed is asserted about the specific character of functioning 

 in its different types, by proving that one of the general 

 features of all functioning may comparatively easily be 



1 I should think that the problem of the re-establishment of irritability, 

 in principle at least, arises even when there is not a trace of so-called 

 "fatigue" or of a "refractory period." The process of restoring may be so 

 rapid as not to be noticeable, nevertheless some sort of restoring is to be 

 postulated. We may say the " irritability " of an elastic ball is re-established 

 by its elasticity. A certain analogy to this case may perhaps be found in the 

 muscle. But the irritability of nerves with respect to nervous conduction, 

 and of glands with respect to secretion, or of the articulations of Mimosa 

 may be well understood, hypothetically at least, if we assume that the 

 ordinary course of metabolic events is apt in itself to lead to a certain state 

 or condition of the organs in question upon which their irritability is based. 

 Certain general conditions of functioning, as for instance the presence of 

 oxygen for the contraction of the muscle, would better be looked upon as 

 necessary "means" of functioning than as being part of irritability as such. 

 " Fatigue," of course, may also be due to the absence of such "means " or to 

 abnormal conditions originated by functioning itself. 



