STATES OF INSECTS. (Jmago.) 297 
Reaumur found to depend upon the expansion of the 
previously compressed segments of the animal by means 
of the included air*. Both in this instance and in that 
of insects whose wings only require expansion, the size 
of the imago often so greatly exceeds that of the pupa, 
that we can scarcely believe our eyes that it should have 
been included in so contracted a space. The pupa of 
one of the beautiful lace-winged flies (Chrysopa Perla) 
is not so big as a small pea, yet the body of the fly is 
nearly half an inch long, and covers, when its wings and 
antennee are expanded, a surface of an inch square. 
When the development of the perfect insect is com- 
plete, and all its parts and organs have attained the re- 
quisite firmness and solidity‘, it immediately begins to 
exercise them. in their intended functions; it walks, 
runs, or flies in search of food; or of the other sex of its 
own species, if it be a male, that it may fulfill the great 
end of its existence in this state—the propagation of its 
kind. Previously to thus launching into the wide world, 
or at least immediately afterwards, almost all insects dis- 
charge from their intestines some drops of an excremen- 
titious fluid, often transparent, and sometimes red. I 
have before related to you the alarm that this last cir- 
cumstance has now and then produced on the minds of 
the ignorant and superstitious’. Whether this excre- 
* Reaum. iil. 378. > Ibid. 385. 
“ Insects of the beetle tribe, especially such as undergo their me- 
tamorphosis under ground, in the trunks of trees, &c., are often a 
considerable time after quitting the puparium before their organs 
acquire the requisite hardness to enable them to make their way 
to the surface. Thus, the newly-disclosed imago of Cetonia aurata 
remains a fortnight under the earth, and that of Lucanus Cervus, 
according to Résel, not less than three weeks. 
4 See above, Vou. I. p. 34—. 
