328 THEORY OF THE SYSTEM. . 222. 



sequence of the divisions not having been effected in a 

 single series of characters, but in several series at once. 



Let the forms of several individuals in a species be re- 

 presented by R, R + 1 ... ; their colours by a, a' ... ; the 

 rest of those characters which produce series by p, p' ... ; 

 the individuals themselves will be represented by the fol- 

 lowing aggregates : 



R; R + 1; R + 2; R + 3 ... 



a a' a" a'" ... 



p p' p" p"' ... 



If we divide here only in the series of the forms, so as 

 to ascribe the members R and R + 1 to the first division 

 or sub-species, R + 2 and R + 3 to the second, the in- 

 dividuals uniting the rest of the characters will fall either 

 in the first or in the second of these divisions. But 

 if the division at the same time extends to the co- 

 lours, and determines, that besides the mentioned forms, 

 the first sub-species should be of the colours a and a' ; 

 the second, besides its peculiar forms, of the colours a" 

 and a'" ; all the compositions like (R + 1). a", (R + 2). a' 

 will not belong to any one of those divisions, although 

 they occur as generally in the species as any one of 

 those contained in the two sub-species. Many divisions 

 are found in mineralogical works, of the description 

 above mentioned. These divisions within the species, 

 in whatever character they may be effected, must always 

 remain entirely arbitrary, and on this account they never 

 will be unanimously received. ' It is much more useful to 

 suppress them altogether, which is the plan adopted in the 

 course of this work.* 



* The application of Mineralogy to the objects of every 

 day's occurrence, may require to give particular attention 

 to certain varieties, which have been employed in the arts, 

 and provided with particular names. This will be proper- 

 ly attended to in the second volume of this work ; but not 

 being of any scientific value, it is foreign to our present 

 consideration. 



