530 ALGEBRA AND ANALYSIS 



of pure and applied mathematics. The number of problems that re- 

 main to be solved are numerous. Excepting the lowest cases as to 

 the number of variables and the order of the invariants, not much 

 more than the mere existence of the invariants is known, so that 

 we have hardly the right to speak of a theory of these invariants. 



When it comes to the question which of the different methods 

 will be best adapted to a further systematical study of the subject, 

 it seems probable that a combination of two or more of them will 

 be the most promising one. But here, as always, it is the man, not 

 the method, that solves the problem. 



