568 INVESTIGATION OF INSECTS. 



above, only a sexual character*. Authors also in their 

 descriptions in this respect sometimes mislead the young 

 student. When Linne calls the thorax of Aphodius er- 

 raticus smooth (l<zvis), he would not expect to find it co- 

 vered with impressed puncta, and with a longitudinal 

 posterior impressed line. Likewise in describing Chlcenius 

 vestitus and nigricornis, Fabricius passes without notice 

 their punctate surface, so different from that of other 

 Harpalidce. Errors of this kind however, it is but fail- 

 to observe, are chiefly to be attributed to the circum- 

 stance that both Linne and Fabricius rarely employed 

 a microscope in making descriptions; though no one now 

 attempts this, except where insects are large, without 

 such an aid. 



If you ask, How am I to acquire this delicacy of tact 

 which is to decide when the terms of a specific character 

 are to be rigidly adhered to, and when taken with a cer- 

 tain latitude ? I answer, In the same way in which a 

 connoisseur attains the faculty of discerning the works 

 of different masters in painting; by such careful study 

 of your author as will make you master of his style. 

 Thus you will soon perceive in what cases expressions 

 are to be taken literally and strictly, or with some al- 

 lowance and abatement. 



TheVe yet remains more distinctly to be adverted to, 

 the assistancethat may be derived in the investigation of 

 insects fromjigures. Generally speaking, these should 

 never be referred to in the first instance, but be regarded 

 as a resource when the ordinary methods leave the sub- 

 ject of inquiry doubtful. Those who begin their ento- 



a VOL, III. p. 304. 



