j^lood of Imccts. 53 



to the best nntliorities, there are uo special vessels to carry the 

 blood to various organs. Nor are [hey necessary, as this 

 nutritive fluid everywhere bathes the ahmcnlary canal, and 



Tifi. in. 



Nervous system of the Drone magnified four times. 



thus easily receives nutriment, or gives waste by osmosis, 

 everywhere surrounds the tracheaj or air-tubes — the insect's 

 lungs — and thus receives that most needful of all food, oxygen, 

 and gives the baneful carbonic acid, everywhere touches the 



