204 
Psyche 
[December 
may have a similar effect upon the tarsal organs of the flies. 
Flies are not attracted to a solution of pure urea. 
Bibliography 
Minnich, D . E. 
1921. An experimental study of the tarsal chemoreceptors of 
two nymphalid butterflies. 
Jour. Expt. Zoo!., 33, pp. 173-203. 
1922. The chemical sensitivity of the tarsi of the red admiral 
butterfly, Pyrameis atalanta Linn. 
Jour, Expt. Zooh, 35, pp. 57-81. 
1922. A quantitative study of tarsal sensitivity to solutions 
of saccharose in the red admiral butterfly, Pyrameis 
atalanta Linn. 
Jour. Expt. Zool., 36, pp. 445-457. 
1926. The chemical sensitivity of the tarsi of certain muscid 
flies. 
Biol. Bui., 51, pp. 166-178. 
Parman, D. C. 
1927. Chemotropie tests with the screw worm fly. 
U. S. D. A. Bui. No. 1472. 
