410 SYSTEM OF INSECTS. 



sidering a numerical arrangement of the Kingdoms of 

 Nature is the value of the component members of each 

 group. It is by no means difficult to divide a Kingdom, 

 a Class, or an Order into two, or three, or five, or seven 

 or more groups, according to any system we may be in- 

 clined to favour ; but it is not so easy to do this so that 

 the groups shall be of equal rank. Yet it seems re- 

 quisite that in grouping our objects, as we descend to- 

 wards the lowest term we should resolve each only into 

 its primary elements, and of them form the next group ; 

 and so on till we come to species. When I say of equal 

 rank, I do not mean an exact parity between the mem- 

 bers into which a group is primarily resolvable, because 

 there will always be a degradation in descensu from the 

 perfection of the type ; but merely that parity (to use a 

 metaphor) that there is between children of the same 

 mother, differing in their relative ages and approach to 

 the perfection of their nature. Perhaps it may be ob- 

 served with respect to the quinary system, that this con- 

 dition is not complied with, since two of the groups taken 

 per se appear really to form one group ; or to be much 

 nearer to each other than to the remaining groups. But 

 when it is taken into consideration that this great group, 

 always resolvable into two, is the typical group, and that 

 the two are really equal, or rather superior in value to 

 the three others, the objection seems to vanish. 



With regard to all numerical systems we may observe, 

 that since variation is certainly one of the most universal 

 laws of nature, we may conclude that different numbers 

 prevail in different departments, and that all the num- 

 bers above stated as prevalent are often resolvable or 

 reducible into each other. So that where Physiologists 



