Blood of Insects. 



53 



to the best authorities, there are no special vessels to carry the 

 blood to various organs. Nor are chey necessary, as this 

 nutritive fluid everywhere bathes the alimentary canal, and 



Via. 10. 



Nervous system of the Drone magnified four times. 



thus easily receives nutriment, or gives waste by osmosis, 

 everywhere surrounds the trachese 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 



