DIGESTION 53 



waterhouse, d. f. Ann. Rev. Entom., 2, (1957), 1-18 (digestion in insects: 

 review) 



wigolesworth, v. b. Tijdschrift Ent., 95, (1952) 63-68 (symbiosis in blood- 

 sucking insects: review) 



The Principles of Insect Physiology, 6th Edn. 1965, 427-464 (digestive 



system of insects) 



