4 PROCEEDINGS OF THE ACADEMY OF [Jan., 



In studying the musculature to determine the homology of the 

 sclerites, the so-called "Halbierungs methode" was largely employed. 

 Usually a series of dissections was prepared, in each case an additional 

 layer of muscles being removed, beginning at the mesal surface of 

 the bisected insect. The preparations thus made were fastened upon 

 thin strips of mica, by means of photoxylin, and preserved in 80% 

 alcohol. Since both mica and photoxylin are transparent, the speci- 

 men may thus be easily studied from either side. 



Only in the case of very small insects, or when it was difficult to 

 follow the course of certain muscles, was it necessary to have recourse 

 to reconstructions from microtome sections. 



In dealing with strongly chitinized material, good preparations 

 could be obtained only by the celloidin-paraffin embedding method, 

 and even then it was frequently necessary to paint the upper face of 

 the block with a thin film of mastix collodion before cutting each 

 section. 



For general purposes, staining with Grenadier's haemotoxylin, 

 differentiating with picric acid, and counterstaining with eosin gave 

 good results. 



Literature. 



The works of Swammerdam, Linne, and all authors before Illiger's 

 time have but little interest other than from an historic point of view. 

 On the other hand such of the later publications as those of Chabrier, 

 '20; Strauss-Diirkheim, '28; Kirby and Spence, '28; Westwood, '39; 

 Burmeister, '32, etc., although very thorough and painstaking, are 

 too confusingly varied in their homologizing and terminology to have 

 •any very great practical worth. 



The most scientific handling of the subject is to be found in the 

 work of Audouin, '24, upon whose researches the modern terminology 

 is based. Since the appearance of this article, but little has been 

 added to our knowledge of the comparative morphology of the thorax. 



Of the more modern publications the following were found very 

 useful in the preparation of this paper: For the homologizing of the 

 sclerites, Kleuker, '83; Kolbe, '93; Brauer, '88; Amans, '85; Borner, 

 '03; Verhoeff, '03; Janet, '98; Comstock, '02; Walton, '00, and Voss, 

 '04. For the terminology of the musculature, Luks, '83; Petri, '99; 

 Breed, '03 ; Voss, '04, and Durken, '07. For the wing venation, Adolph, 

 '80; Redtenbacher, '86; Comstock, '98, and MacGillivray, '06. 



Such of the works as are of a more particular interest will be dis- 

 cussed under those headings to which they especially refer. 



