ON THE NERVOUS SYSTEM OF THE LARVA OF CORYDALIS 



CORNUTA L.* 



B}^ A. G. Hammar. 



Owing to its large size and to the ease with which the parts 

 may be dissected, the larva of Corydalis cornuta L. is especially 

 favorable for the study of the nervous system. In spite of this 

 fact, only fragmentary work has been done upon this species, and 

 the present investigation was undertaken for the purpose of 

 making a comprehensive study of the larval nervous system as 

 w^ell as for verifying the work already done. 



Leidy '48 pictures and describes in a general way the nervous 

 system of the adult insect, which in various respects differs from 

 that of the larva. The only general discussion of the larval ner- 

 vous system is that of Comstock and Kellogg '95. Though 

 thoroughly accurate, this description is very concise, covering 

 only the features of interest to the elementary student. 



A detailed study of a limited region is that of Krauss '87, 

 who confined his studies to the nervous system of the head of 

 the larva. Although inaccurate in some details, his work is a 

 valuable contribution to the knowledge of the nervous system 

 and has been of much value to me in preparing this paper. 



In 1895 an investigation was begun by Miss M. A. Nichols, 

 for the purpose of determining the existence of a secondary 

 nervous system such as that described by Newport '32 and '34. 

 Unfortunately, this work was never finished, though promising 

 interesting results. The notes and drawings were deposited 

 in the entomological library of Cornell University, and in the 

 study of certain features have been used to advantage by the 

 writer. 



For the material used, I am indebted to my friend, Mr. C. W. 

 Palmer, of Westtown, Pa., who on different occasions has been 

 kind enough to send me an abundant supply of living larvae 

 from that locality. To Prof. J. H. Comstock I wish here to 

 express my sincere acknowledgment for aid and encouragement 

 liberally bestowed. For suggestions and aid received from mem- 

 bers of the Entomological Staff' of Cornell University, and most 

 especially from. Prof. W. A. Riley, under whose guidance this 

 investigation has been carried on — I wish to express my sincere 

 gratitude. 



* Contribution from the Entomological Laboratory of Cornell University. 



105 



