294 



ptilota: internal anatomy. 



144 



branch of zoology ; for whilst it is almost impossible to 

 preserve other invertebrated animals, except in spirits, 

 and the vertebrata, except by stuffing the skin, whereby 

 the form of the body is entirely dependent upon the 

 fancy of the person who " puts up " the specimen, in- 

 sects, in almost every instance, preserve their form and 

 colour with a freshness often quite equal to the life. 

 It remains for me, therefore, to notice (which I shall do 

 in the most concise manner) the internal systems of 

 sensation, digestion, circulation, respiration, motion, and 



generation. 



A. The Sensitive or Ner- 

 vous System. — The chief 

 means whereby the inter- 

 course of animals with the 

 external world, by the instru- 

 mentality of the senses, is 

 maintained, is the nervous 

 system, originating in the 

 brain or the spinal cord. 



Hitherto this branch of our 

 subject, and indeed the inter- 

 nal structm-e of insects in 

 general, has received too little 

 attention from entomologists, 

 of whom we are compelled 

 to say, that mere external 

 form and the collecting of 

 specimens occupy their chief 

 attention. Swammerdam was 

 the first author who carefully 

 traced the nerves of several 

 insects, as the bee, the silk- 

 '"^::^i!I^^'^.^u^ne»\:;^^ worm, and the Oryctes nasi- 



cate the situation of nerves concealed by ■ ^ . t i. „„„ ^„,. 



the incumbent muscles. COmiS J DUt lAOUnCt W aS lai 



