ANDROCONIA 



109 



is applied the term androconia. They are found, almost without 

 exception, on the upper side of the fore wings, occurring in limited 

 areas, such as the discal spots, or on folds of the wings. Fritz 

 Miiller has shown that they function as scent-scales, and are con- 

 fined to the males. Kellogg has detected androconia-like scales on 

 the wings of a caddis-fly, Mystacides punctata (Fig. 229). 



Thomas has proved by sections of the wing of Danais, etc., that 

 the androconia arise from glands situated in a fold of the wing 

 (Fig. 230), and he states 

 that the material elabo- 

 rated by the local glands, 

 and distributed upon the 

 surface of the wing by a , 

 the androconia, is that 

 which gives to many of 

 the Lepidoptera their 

 characteristic odor. On 

 comparing these 

 " glands," it is evident 

 that they are groups of 

 specialized formative 

 cells of Semper (tricho- 

 gens), which secrete an odorous fluid, issuing perhaps from extremely 

 fine pore-canals at the ends of the androconia. They thus corre- 

 spond to the glandular hairs, poison-hairs, and spines of caterpillars, 

 the formative cells of which contain either a clear lymph or poison. 



Fro. 230. Cross-section of androconia surface on wing of 

 ThecJa cahi nun: a, androconia; gl, gland of base; *, 

 ordinary scales ; ir, wing in section. After Thomas. 



LITERATURE 

 a. Hairs, bristles, cleaning spines, calcaria, combs, etc. 



Leydig, Franz. Zum feineren Bau der Arthropoden. (Miiller's Archiv f. Anat. 



und Phys., 1855, pp. 376-480.) 



Forel, Auguste. Les fourmis de la Suisse. Bale, 1874. 

 Saunders, Edward. Remarks on the hairs of some of our British Hymenoptera. 



(Trans. Ent. Soc. London, 1878, pp. 169-171.) 

 Perez, J. Notes d' apiculture. (Bull. Soc. d'Apic. de la Gironde, Bordeaux, 



1882.) 



Osten Sacken, C R. von. An essay on comparative chsetotaxy, or the arrange- 

 ment of characteristic bristles of Diptera. (Trans. Ent. Soc. London, 1884, 



pp. 497-517.) 

 Preliminary notice of a subdivision of the suborder Orthorrhapha Brachy- 



cera (Diptera) on chaetotactic principles. (Berlin Ent. Zeitschr., 1896, 



pp. 365-373.) 



