bo 
Wn 
CLASSIFICATION 
sawflies (Tenthredinide), judging from their resemblance to 
mecopterous and lepidopterous larve ; and the simple, maggot- 
like form of the larve of ants, bees, wasps and parasitic 
* Hymenoptera is due to secondary modifications in correlation 
with their sedentary mode of life. 
In Diptera and Hymenoptera the phenomenon of metamor- 
phosis attains its greatest complexity, as was remarked. 
Opinions differ as to which of these two orders is the more 
specialized. Hymenoptera are commonly called the “ high- 
est” insects, when their remarkable psychological development 
is taken into account; but from a purely structural standpoint 
it is hard to say which order 1s the more complex—aindeed, the 
two orders are specialized in so many different ways that no 
precise comparison can be made between them. 
The following diagram (Fig. 32) is a graphic summary of 
what has just been said in regard to the genealogy of the 
DIPTERA 
PLECOPTERA 
PLATYPTERA 
SIPHONAPTERA 
THYSANOPTERA 
ORTHOPTERA HEMIPTERA 
COLLEMBOLA 
COLEOPTERA THYSANURA 
Genealogical diagram of the orders of insects. 
The positions of Hemiptera and Coleoptera 
orders of insects. 
The central sroup (7) 1s the 
are most open to criticism. 
