SYSTEM OF INSECTS. 421 
should be a mutual imitation in all the states of any two 
insects. Wherever we discover a marked resemblance 
between two perfect insects, there is a true analogy, 
though their metamorphosis may diner; and where there 
is not that resemblance, though the metamorphosis may 
agree, there is no analogy. In fact, insects are some- 
times analogous in their first state and not in their last ; 
and at other times analogous in their last and not in their 
first : but the analogy is most perfect when it holds in 
all their states : it then, indeed, almost approaches to an 
affinity. They may also be analogous to each other in 
their habits and economy, when there is little or no re- 
semblance in their form ; and, vice versa, be analogous in 
their form and not in their habits. So that different sets 
of analogies may be assumed as foundations for different 
systems. Thus Mr. MacLeay assumes the metamor- 
phosis as the basis of analogy between the corresponding 
Orders of Mandibulata and Haustcllata a , while M. Sa- 
vigny compares the perfect insects b : the result therefore 
differs in some instances. I shall now lay before you 
in a tabular view their plans and my own. 
Savigny. 
Mandibulata. Haustellata. 
Neuroptera 1 f Lepidoptera 
Ascalaphus J " ' ( Papilio 
Hymenoptera 1 f Diptera 
Euccra J " ' I Tabanus 
Orthoptera \ ( Homoptera 
Locusta L. ) '" \ Cicada 
Aptera ) f Aphaniptera 
Nirmus ) '" \Pulex. 
Hor. Eniomolog. 45G. Comp. Linn. Trans, xiv. 67 
Mem. tur let An'uii, mm Vertebr, I. i. 20—. 
