CHAPTER VII. 
SYNTHETICAL GROUPING OF THE ANIMAL KINGDOM. 
Having thus built up the province of vertebrated ani¬ 
mals, and having assigned to these apparently hetero¬ 
geneous forms a common and clearly natural character or 
bond of union, it next becomes desirable to inquire briefly 
into the structure and systematic divisibility of the inver¬ 
tebrate tribes, by which I believe the vertebrate to be sur 
rounded. United by several very marked characters, and 
by these also clearly shown to be inferior to the Verte- 
brata, it is still necessary to seek among them other cha¬ 
racters by which to distinguish them inter se , and this is 
by far the most difficult part of this synthetical enquiry, 
and the one of which the result is least likely to be satis¬ 
factory, on account of the general ignorance which pre¬ 
vails on almost every branch of the subject; the insects 
perhaps (owing to the labours of Swammerdam, Willughby, 
Ray, Linneus, DeGeer, Fabricius, Clairville, Latreille, and 
our illustrious countryman, Leach), may be deemed an 
exception, and it was through the assistance afforded by 
these able pioneers that I was enabled to attain sufficient 
knowledge of insects to employ them formerly as affording 
the best illustration and test of my opinions. 
