JOURNAL, OF ENTOMOLOGY AND ZOOLOGY 95 



LIST OF IMPORTANT REFERENCES 



(1) DeGeer, Ch. (1775). Memoires pour servir a I'histoire des insectes, V., pp. 



291-292. 



(2) Lyonet, P. (1832). Recherches sur ranatomie et les metamorphoses des diffe- 



rentes especes d'insectes. Ouvrage posthume, public par M. W. deHaan, pp. 

 124-127. 



(3) Ratzeberg, J. T. Ch. (1839). Die Forstinsecten, Part 1, p. 246. 



(4) Claus, C. (1662). Ueber die Seitendriisen der Larven von Chrysomela populi, 



Zeit fiir Wiss. Zool. XI, pp. 309-314. 



(5) Dimmock, G. (1882). On some glands which open externally on insects. Psyche 



III, p. 392. 



(6) Packard, A. S. (1895). The eversible repugnatorial scent glands of insects. Jour- 



nal New York Ent. Soc. Ill, p. 1.15. Also in his text-book of Ent. (1898), 

 p. 374. 



(7) Schroeder, Chr. (1912). Handbuch der Entomologie V, p. 37. 



(8) Candeze, E. (1875). Les moyens d'attaque et de defense chez les insectes. Bull. 



Acad. Royale de Belgique, 2 ser. XXXVIII, p. 805. 



(9) Berlese, A. (1909). Gli insetti, p. 527. 



LEGENDS 



Figure 1. Semidiagrammatic representation of the gland in its retracted position. 

 Pr. c, primary cuticula ; Sc. c, secondary cuticula; Hp., hypodermis; Ep. R. and Ep. 

 ^R., epithelium of the reservoir; Gl, glandular cells; Sp., space between hypodermis 

 and epithelium of reservoir where blood is forced in; M^ and M^, musculature of the 

 reservoir. 



Figure 2. Gland in its eversed position. 



Figures 3-12 are drawings of section of gland. In all these the chitin is seen torn 

 away from the hypodermis, due to shrinkage of the latter in the processes of sectioning. 

 Wherever the hypodermis is seen more than one layer thick, it is because the section at 

 this point has been cut tangentially, close to the surface. 



Figure 3. Longitudinal section of a thoracic tubercle with the gland inside. R., 

 reservoir; W. bd., wing bud; In., intima ; Ep. F., epithelial fold, caused by blood pres- 

 sure against retention of muscle M^ ; Trg., Trichogen cell; Tr., trachea; Ep 2, piece 

 of epithelium torn away from Ep 1 ; the rest as in Fig. 1. 



Figure 4. Section following that of Fig. 3. 



Figure 5. Section following that of Fig. 4. 



Figure 6. Section at right angles to plane of Figs. 3-5, showing attachment of muscle 

 M^. Ri and R^, portions of folds of reservoir; Ep^ and Ep^, sections through longi- 

 tudinal fold of epithelium ; M, peripheral body muscle. 



Figure 7. Section in same plane as Fig. 6, showing muscle M^ ; M, peripheral body 

 muscle; M-, muscle of reservoir. 



Figure 8. Section in same plane as 7, showing position of muscle M^, where gland 

 is eversed ; T, top of tubercle. 



Figures 9, 10 and 11. Glandular cells. N, nucleus; N^, nucleus of guard cell; C^, 

 chitinous canal ; Gr. granules. 



Figure 12. Portion of the epithelium of the reservoir. Ep R, epithelial cells; I, 

 intima. 



