126 BRITISH BEES. 



monograph of European Ichneumons ; Erichson's ela- 

 borate work upon the Staphylinidse ; and our own Kirby's 

 'Monographia Apum Angliae/ Their perfection con- 

 sists in fulfilling thoroughly all the above conditions, 

 for if any doubt exist upon comparing your insect with 

 their descriptions, you may be fully assured yours is 

 not identical. The only drawback to the utility of Mr. 

 Kirby's book is that he had to deal with insects variable 

 in condition from many causes, and the variable state of 

 the insect that may have to be compared ; his descrip- 

 tion has evidently been made sometimes from a worn 

 specimen, one that had been exposed to wind and 

 weather, and sometimes from an insect in fine condition. 

 Thus it is important that compared insects should be in 

 an identical state to substantiate the comparison, a diffi- 

 culty which this family has specially to contend with, as 

 these insects are more liable than almost any others to 

 vary, owing to their specific character depending much 

 upon pubescence, which is extremely subjected to many 

 modifying influences, for the tinges and positive colour 

 of the hair will much vary by exposure, as it is not pos- 

 sible always to capture a bright individual. 



Taking specific description thus practically in its full 

 and wide sense, it is requisite, for the purpose of avoid- 

 ing repetition, that all the characters of the superior 

 combinations should be eliminated, leaving it with those 

 only which have not been thus absorbed, which now 

 constitute its sole remaining distinctive specific pecu- 

 liarities. Every species necessarily contains within it- 

 self, every character of every combination in direct line 

 above it, although these have been gradually abstracted 

 to form those several combinations which are arrived 

 at successively in the synthetical ascent. Analytically, 



