author's abstract of this paper issued 

 by the bibliographic service, december 27 



THE CHEIMICAL SENSITIVITY OF THE TARSI OF THE 

 RED ADMIRAL BUTTERFLY, PYRAMEIS 

 ATALANTA LINN. 



DWIGHT E. MINNICH 



Department of Animal Biology, University of Minnesota 



THREE FIGURES 



CONTENTS 



Introduction 57 



General methods 58 



Experiments with local stimulation of individual tarsi 64 



Experiments with simultaneous stimulation of all ambulatory tarsi 68 



General summary and conclusions 80 



INTRODUCTION 



In a previous paper (Minnich, '21) I showed that the tarsi of 

 the butterfly, Pyrameis atalanta Linn., are sensitive to contact 

 with certain substances in solution, and hence must possess con- 

 tact chemoreceptors. In the same paper I also presented some 

 preliminary data indicating what kinds of substances the animals 

 were thus enabled to discriminate. It is the purpose of the pres- 

 ent paper to give a further account of the qualitative range of 

 sensitivity of these tarsal organs. 



In the present work I have employed the same general methods 

 as before, with two exceptions. First, instead of using both 

 captured specimens and those hatched in the laboratory, only 

 butterflies hatched in the laboratory have been employed. The 

 complete adult history of every specimen was thus a known and 

 controlled one. Second, a few animals have been studied, under 

 varying nutritional conditions, over a long period of time, rather 

 than a number of animals, in the same nutritional condition, for 

 a short period of time. Indeed, the data to be presented have 

 been obtained from but eight specimens, and chiefly from four 

 of these. These four butterflies, however, were kept under very 

 close observation for 19, 27, 29, and 30 days, respectively. 



57 



