56 
Psyche 
[June 
broken when the inner end of the stomodaeum pushes 
through. The peritrophic membrane, as described by Wig- 
glesworth, is chitinous and arises from a mass of cells cor- 
responding in position to the base of the stomodaeum in the- 
embryo. This indicates that the peritrophic membrane is 
ectodermal in origin. 
Literature Cited 
Campbell, F. L. 1929. The detection and estimation of in- 
sect chitin; and the irrelation of chitinization to hard- 
ness and pigmentation of the cuticula of the American 
cockroach, Periplaneta americana L., Ann. Ent. Soc. 
Am., Vol. 22, pp. 401-426. 
Nelson, J. A. 1915. The embryology of the honey-bee, 
Princeton University Press, pp. 1-282. 
Snodgrass, R. E. 1925. Anatomy and physiology of the 
honey-bee. McGraw Hill Book Co., New York, pp. 
1-327. 
Wigglesworth, V. B. 1930. The information of the peritro- 
phic membrane in insects with special reference to the 
larvae of mosquitoes. Quart. Jour. Mire. Sc., Vol. 
73, Part IV, pp. 593-616. 
