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TEXT-BOOK OF ENTOMOLOGY 



retracted by the muscle (m); at the bottom of the crater are the 

 secreting or glandular cells (gc), being modified hypodermal cells. 

 These doubtless serve as terrifying organs to ichneumons and other 

 insect enemies, and though we have been unable to detect any odor 



emanating from the tubercles, 

 yet possibly they give out a 

 scent perceived by and dis- 

 agreeable to their insect assail- 

 ants. 



In the Hemileucidse there is 

 a pair of lateral osmeteria, on 

 the 1st and on the 7th abdomi- 

 nal segments, which, however, 



are not highly colored (Figs. 363, 366, 10). In Megalopyge (Lagoa, 

 Fig. 364) there is a lateral row of singular pale permanently everted 

 processes which appear to be the homologues of the osmeteria of 

 larvae of other lepidopterous families. As these are repeated on 

 seven segments, their metameric arrangement is obvious. The rela- 

 tion of these curious glands to the viscera is seen in Fig. 297, Igp, 

 and their minute structure in Fig. 365. 



At A, the lumen (?) is a deep narrow cavity, with the secretion (seer.), col- 

 lected at the mouth of the cavity, composed of a thin, mucus-like, coagulated 

 fluid, containing granules of varying degrees of fineness, which take the stain 



FIG. 363. Freshly hatched larva of Ifyper- 

 chiria -i<>, with its two pairs of eversible glands (g). 



FIG. 864. Young larva of Megalopyge crixpata, enlarged, showing the seven pairs of lateral 

 processes (Ip) : sp, spiracle ; abl' ', abl a , six pairs of abdominal legs besides the anal pair. 



readily. Outside of these are collected fine nuclei (6c), stained dark, and 

 enveloped in a slight, transparent, pale, protoplasmic envelope, which may be 

 blood corpuscles. The glandular cells themselves are simply modified hypoder- 



