INTRODUCTION. 59 



some authors as absorbents. From having observed 

 them chiefly in long and slender trunks, Reaumm* 

 was led to conceive^ that their only use is to render 

 that organ more steady, by affording numerous points 

 of support, and adhering in some degree to the sub- 

 stances into which it is inserted; — an explanation 

 rendered highly probable by the fact, that the long 

 and slender ovipositors of Ichneumons, and many 

 other insects, are generally provided with some point- 

 ed projections near the tip, evidently intended for 

 his purpose. — Several of the figures on Plate I. are 

 designed to illustrate the structure of the organ just 

 described. Fig. 9, is a magnified view of the trunk, 

 showing its general form, and the projecting points 

 near the tip (a). Fig. 10, is a highly magnified sec- 

 tion, exhibiting the two portions (a, b) of which it is 

 composed, each of them tubular {d, d), and forming 

 by their junction a central canal {e). Fig. 11, is 

 another section, representing the under side. 



The two portions of which the proboscis is com- 

 posed, seem to be analogous to the maxillae or un- 

 der jaws of the mandibulated tribes, and to receive 

 their great development at the expense of the other 

 oral appendages, most of which are small and incon- 

 spicuous. This is not the case, however, with the 

 labial palpi, which are generally of Considerable size, 

 and curved upwards in such a manner as to form two 

 projecting points in front of the head. These or- 

 gans are covered with hair-like scales, are usually of 

 a somewhat conical shape, and consist, for the most 

 part, of three articulations. (Sec PI. I. fig. 12 a 



