480 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1925 



microscope, which at once revealed the cause of attraction, for 

 there on the tenth segment he found a small transversely elongated 

 gland on the dorsal surface. 



He then examined with the microscope another larva in the same 

 stage while it was feeding, during which operation the gland is 

 ke]5t throbbing. So he placed the ants close to it, and soon saw 

 them run over it. Directly a foot touched the gland, or the region 

 adjacent to the gland, it throbbed more violently and swelled up. 

 It then exuded a globule of clear white liquid. At the same instant 

 an ant licked up the drop. In a few seconds an ant's foot again 

 toi'.ched the gland, and another bead of liquid oozed out, which 

 was at once again licked up by an ant. 



An interesting fact was that the larva did not heed the ants run- 

 ning over and around it while it kept feeding; but the gland is 

 apparently extremely sensitive to the touch of an ant's foot. 



He several times touched the glands of several different larvae 

 with the point of a very fine sable-hair brush. This caused the 

 larvse at once to wince and to contract; but in no way could he 

 induce the exudation of the liquid. But as soon as an ant's foot, or 

 the claws of the foot, touched it a bead would appear, to be at 

 once imbibed by the ants. 



Although the larva was kept in a box with numerous ants, both 

 workers and winged females, together with their pupse, not one 

 attempted to bite it; as soon as they touched it they slowly closed 

 their jaws and waved their antennoe over and upon it. 



The larvae appeared to be perfectly at home with the ants, neither 

 molesting the other. After the third molt Mr. Frohawk was un- 

 able to perceive any attempt at cannibalism among the caterpillars, 

 although this habit exists in all the earlier stages. 



On July 12, 1905, when in company with Mr. A. L. Rayward, 

 Mr. Frohawk discovered a living pupa of Lycmna arion, and near by 

 a p'upa case of a freshy emerged female which Mr. Rayward de- 

 tected at rest. 



As described by Mr. Frohawk the pupa bears a general resemb- 

 lance to the pupa of Lycoena oigon^ except for its much larger size, 

 measuring half an inch in length. In dorsal view across the middle 

 its greatest width is three- fourteenths of an inch. The head is ob- 

 tuse, the base of the wings is slightly angular and swollen, the wing 

 is slightly concave, and the abdomen is swollen at the third and 

 fourth segments, becoming thence attenuated and rounded pos- 

 teriorly. 



In side view the pupa measures three-sixteenths of an inch across 

 the middle. The head is rounded, the thorax convex and rising 

 into a slight dorsal ridge, the metathorax and first abdominal seg- 



