212 CHARLES W. HARGITT. 



is erroneous, "The body of the insect during flight not being 

 lightened by the air in the sacs." Submitting this point to two 

 of my colleagues of the department of physics, Doctors Porter 

 and Packard, I am assured that it is entirely correct. 



It seems rather certain, therefore, that neither from its struc- 

 ture, nor yet from the "old prosaic explanation " of an adaptation 

 to aerial life, does he sustain his conclusions. Granting the 

 ramifications of tracheae over the organ no more makes it respira- 

 tory than does a similar disposition of tracheae over the viscera 

 or the musculature constitute them such. Apart from the names 

 by which Graber designates the organ, namely, "Tracheenblase" 

 and "Luftsacke," there is nothing in his account which supports 

 the views of Snodgrass. Graber 's problem was the "Tympanal- 

 organe," not respiration. I believe therefore that Snodgrass 

 has misconstrued Graber's work so far as it is applicable to the 

 matter at issue, and that his view may be dismissed as devoid of 

 structural or functional evidence as a respiratory organ, or as an 

 accessory "Tympanal organ," as claimed by Graber (p. 282-3). 



LITERATURE CITED. 

 Graber, Vitus. 



'77 Die Insecten, Miinchen. 



'76 Die abdominalen Tympanalorgane der Cicaden u. Grylloden. Denkschr. 



d.k. Akad. d. wissen. Math., natur classe, Bd. 36, pp. 273-296. 

 Greene, C. W. 



'14 Storage of Fat in the Muscular Tissue of the King Salmon and its Resorp- 

 tion During the Fast of the Spawning Migration. Bull. Bur. of Fisheries, 

 Vol. 33, pp. 73-138. 

 '14 Fat Absorbing Function of the Alimentary Tract of the King Salmon. 



Ibid., Vol. 33, pp. 149-175. 

 Hargirt, C. W. 



'03 The Periodic Cicada, Proc. Onondaga Acad. Sci., Vol. I., 1903, p. 41. 

 Hickernell, L. M. 



'20 Digestive System of the Periodical Cicada. Ann. Ent. Soc. Am., Vol. 



XIII., pp. 223-242. 

 Marlatt, C. L. 



'07 The Periodical Cicada. Bull. 71, U. S. Bur. Entomol. 

 Packard, A. S. 



'98 A Text-Book of Entomology. 

 Quaintance, A. L. 



'02 The Periodical Cicada and Its Occurrence in Maryland. Bull. No. 87, 



Maryland Agr. Exp. Sta. 

 Snodgrass, R. E. 



'19 The Seventeen Year Locust. Smith. Report 1919, Pub. 1921, pp. 381-409. 



