March, 1912] AlDRICH : LarV^ UsED AS FoOD BY INDIANS. 31 



Explanation of Plate I. 



All about natural size. 



No. I. Two larv£e injected with plaster of Paris. 



No. 2. Four specimens partly injected with gelatin. 



No. 3. Several of the dried specimens as obtained from Indian woman. 



SOME OBSERVATIONS ON THE RELATIONS OF 



ANTS AND LYC^NID CATERPILLARS, AND 



A DESCRIPTION OF THE RELATIONAL 



ORGANS OF THE LATTER. 



By E. J. Newcomer, 

 Sacramento, Cal. 



(With Plates II and III.) 



It has been known for many years that the larvae of certain 

 Lycsenid butterflies are attended by ants. This attention is due to the 

 excretion by the larva, from a slit on the tenth body segment, of a 

 liquid agreeable to the ants. There is also, on the following or 

 eleventh body segment, a pair of evaginable organs of relation (Plate 

 II, Figs. I and 2). These organs have been found in a large number 

 of species, and Wheeler (9) states that the larvae of some sixty-five 

 species are reported to be attended by ants. Certain species, such as 

 Lyccvna sonorensis, feed within the thick leaves or in the bud-clusters 

 of the foodplant. It would be of interest to know whether these 

 larvae have the organs developed to any extent. 



I have made observations on the behavior of ants toward the 

 larvae of Lyccvna fulla (3) and of L. pseudargiolus, var. piasus. I 

 have found the larvae of the latter species very generally attended in 

 the third and fourth instars by the ants Tapinoma sessile and Preno- 

 lepis imparls, and occasionally by Cremastogaster and Camponotus ( ?). 

 I kept a number of the larvae in the laboratory, placing each individual 

 in a separate pill box, and putting with each one or two of the ants 

 which I had found with them. By substituting a disk of glass for the 

 cover of the box, I was able to use a binocular microscope in watching 

 the ants and larvae. 



The typical performance, as I have observed it, is this : An ant, on 



