1893.] Entomology. 1019 
is usually due to the coloring of the large scales that are for their pro- 
tection. The androchonia vary much in form, many of them being 
simply hair-like, others feather shaped or rod-like with a plumed tip. 
In structure they are much softer than the ordinary scales and conse- 
quently much more pliable, which later property serves a very efficient 
purpose in their concealment. There is often a canal extending from 
the base to the tip of the scale where it may find a direct outlet or dis- 
appear in the spongy mass found at the end of a large variety of these 
androchonia. 
At the base of many are found the true ball and socket joints like 
that in the ordinary scales. 
It has been shown by Weisman that the wings of the Lepidoptera 
do contain living tissue and this would allow the production of odors 
through local scent glands. This arrangement has often been conjec- 
tured but it seems that either no attempts have been made at a system- 
atic study of the subject or the attempts have ended in failure. The 
trouble was no doubt due to a lack of care in the preparation of the 
material for study. It was found after repeated attempts that the best 
results were obtained by hardening the freshly removed wing in alcohol, 
infiltrating with collodion and preparing serial sections by the use of a 
microtome. 
The results of careful study and repeated observations on many series 
of sections of various Lepidoptera has shown the androchonia to be the 
outlet of certain glands located in the tissue of the wing beneath the 
androchonia bearing surfaces. The glands in sections were very 
prominent and no doubt of their genuineness could be entertained. 
One especially prominent was found beneath the androchonia in the 
wing of Danais archippus. The character of the surface of the wing 
above the glands is often very interesting, it sometimes being covered 
with a great number of papille from the end of which the scent scales 
project ; or it may be like the ordinary surface of the wing. In the 
former case the androchonia are quite small and but one to each papil- 
la, at the base of which we find the gland. This gives the scent scale 
the appearance of a small rod placed in a flask. In the tissue of the 
wing we find numerous canals ramifying in various directions. The 
material elaborated by the local glands and distributed upon the sur- 
face of the wing by the androchonia is that which gives to many of the 
Lepidoptera their characteristic odor. 
Miiller has been able to recognize more than 30 distinct odors in 
different patches of these scent scales. The use of the odor is no doubt 
in many cases for protection, but it must also assist in sexual selection. 
