. 817. THEORY OF THE SYSTEM. 817 



History. In order to effect this, however, some prepara- 

 tions will be necessary. 



. 217. MUTUAL RELATIONS OF THE NATURAL- 

 HISTORICAL PROPERTIES IN CERTAIN INDIVIDUALS. 



Individuals, which are different from each other 

 in their natural-historical properties, so that their 

 differences constitute members of one and the same 

 series, may thoroughly agree with each other in 

 the rest of their properties. 



Among the different cases comprised under this head, 

 there is one more remarkable than the rest, if the differ, 

 ences of the individuals consist in the forms, and if these 

 forms are members of a series. It deserves to be considered 

 more in particular, since all the others may very easily be 

 explained upon a similar principle. 



Experience confirms, in numerous examples, that forms, 

 which are different, members of the same series, may, in 

 other respects, possess properties entirely equal and similar. 

 A demonstration, however, may be given of this proposition 

 with more generality, and which therefore will receive a 

 greater degree of evidence than that which it could acquire 

 by any number or description of examples quoted. 



It has been observed above (. 139.), that such forms, 

 as are members of one series, may enter into combina- 

 tion with each other, and inversely, that all the combina- 

 tions produced by nature contain only such simple forms 

 as belong to, or represent members of, one and the same 

 series. 



An individual appearing in a compound form, appears at 

 the same time in as many simple forms as the combina- 

 tion contains ; and, in respect to these, it may be consi- 

 dered as representing as many individuals at a time (. 138.). 

 But with every one of these simple forms we find connected 

 the rest of the natural-historical properties of the individual 

 under consideration. These assemblages of properties repre- 



