150 Wisconsin Academy of Sciences, Arts, and Letters. 



chemical and molecular changes of tlie blood sent to the nerv- 

 ous centres are regarded as the true measure of the nervovs 

 force generated. The amount of this force compared with the 

 amount of nervous substance should show the activity. 



ISih.- Relative development of the spnjoalhetic and cerebro- 

 spinal systems. 



The comparative rank of the two systems is unquestioned. 

 The distinct differentiation of the latter from the former marked 

 a large advance upon previous structures. The relations of 

 the two systems must then be indicative. 



The indications of a single one of these rules alone is not to 

 be regarded as decisive. The fallacy of most of the objections 

 that have been urged against such of these rules as have been 

 previously advanced lies here. Because they have not been 

 universally decisive, their value within the sphere of their 

 application and with the modifications and corrections to wliich 

 they are subject, has been falsely estimated. That that sphere 

 and those modifications and corrections can be ascertained and 

 their relations adjusted, is the firm belief of the author. It is 

 the combined and corrected result of all these rules that is to 

 be decisive. And as their indications are not always harmo- 

 nious when two subjects are being compared, the question of 

 their relative value arises. This question, as I have attempted 

 to show, has not by any means the significance it has when 

 applied to a system based upon the various organs of the 

 system. But whether more or less significant, the author is 

 not yet prepared to answer it, except in generalities. 



