1020 The American Naturalist. [November, 
This study was undertaken at the suggestion of Professor J. H. 
Comstock, to whom I am indebted for the material examined. 
M. B. Tuomas, 
Wabash College. 
Description of Plates. 
Fig. 1.— Transection of wing of Danais grepu, Moving the loca- 
tion and arrangement of the androchonia 
“ la.—First venule of the median vein. 
* 16.—Androchonia bearing surface. 
“ 1e.—Glands below the surface and in the tissue of the wing. 
* 1d.—The proliferation of the wing for protecting the surface. 
Fig. 2.—Hind wing of male Danais archippus. 
* 2a.—Location of androchonia (nat. size). 
Fig. 3.—Transection through the marginal vein of the fore-wing of 
Eudamus tityrus showing location of androchonia in the 
pocket formed by folding over the marginal vein 
* 3a.—Marginal vein. 
“ 36 and c.—Other veins. 
* 3d.—Location of androchonia. 
" 3e.—Large scales on the wing that protect the androchonia. 
" 8f.—Edge of the wing. 
Fig. 4.— Transection of the hind wing of Thecla calamus at the place 
where the androchonia are congregated. 
Fig. 5.— View of surface of the wing of Thecla calamus giving the 
arrangement and abundance of the scent scales as compared 
with the ordinary one. (6) Androchonia. 
* ba.—Ordinary scales. 
Fig. 6.— Trans. of wing androchonia surface on the wing of Theela 
calamus. 
* 6a.—Androchonia. 
* 66.—Glands at the base. 
* 6e.— Ordinary scales. 
* 6d.—Wing in section. 
Fig. 7.—Trans. of wing of Thecla calamus, showing the androchonia 
with large gland at base. 
* Ta.—Androchonia. 
* 76.—Surface of wing. 
* Te.—Tissue of wing. 
Fig. 8.—Gland. | 
Fig. 9.—Androchonia. 
Figs. 10 and 11.—Androchonia in trans-and longisection. 
