AN 
INTRODUCTION 
TO 
ENTOMOLOGY. 
LETTER XXXVII. 
INTERNAL ANATOMY AND PHYSIOLOGY 
OF INSECTS. 
SENSATION. 
HAVING given you this full account of the external 
parts of insects, and their most remarkable variations ; 
I must next direct your attention to such discoveries as 
have been made with regard to their Internal Anatomy 
and Physiology : a subject still more fertile, if possible, 
than the former in wonderful manifestations of the 
power, wisdom and goodness of the Creator. 
The vital system of these little creatures, in all its 
great features, is perfectly analogous to that of the ver- 
tebrate animals. Sensation and perception are by the 
means of nerves and a common sensorium ,• the respiration 
of air is evident, being received and expelled by a par- 
VOL. IV. B 
Mil 1 ~ 
