CONCLUSIONS RESPECTING INSECT FOOD. 67 



pliorous Coleoptera), tlie cutworms (in fact all Lepidoptera), and the 

 crane flies (Tipulidse). 



It is evident that the percentage of the three groups of insects 

 forming the chief insect food of the Grow can not be determined from 

 the number of species nor from the bulk represented by the aggregate 

 of each species, but must be determined by the number of specimens. 

 It is difficult to give exact figures on this last point for two reasons, viz : 



1. While it is easy to determine the number of specimens of a given 

 species where there are but few in the stomach, it is often impossible 

 to do so where the number is great and the specimens are in the decom- 

 X)osed condition in which insects are usually found when in such num- 

 bers. In most instances the number could only be approximated by 

 the number of heads or mandibles, as the remainder of the body has 

 been essentially destroyed by digestion. 



2. A large proportion of the stomachs submitted are those of nest- 

 lings, and it follows that the mere fragment of any given insect is 

 counted in such a case as a specimen, while it is probable that a single 

 specimen may have been given in fragments or portions by the parent 

 to several of the nestlings, so that combined they represent but one 

 single individual. Nevertheless the difficulties do not, in my judgment, 

 invalidate the general conclusions arrived at, which are, that the sum 

 total of specimens of those insects which are emphatically injurious to 

 agriculture vastly outnumbers those which may be considered benefi- 

 cial, and that it also surpasses the number of beneficial and innoxious 

 species combined. 



The facts on the whole overwhelmingly speak in favor of the Crow, 

 and taken alone would be at variance with the prevalent opinion hith- 

 erto held and yet held regarding the economic status of the Crow as an 

 insectivorous bird. 



How far these general conclusions may be modified by the indirect 

 nature of the food examined, i. e., by the habit of the Crow of feeding 

 upon toads and frogs and even small birds and other insectivorous 

 animals, I am in no position to determine. It is probable, however, 

 that only a small proportion of the insect food of the Crow is derived 

 in this indirect manner and that in so far the conclusions as to its 

 economic status are not to be modified. 



A complete list of the insects contained in each one of the six hun- 

 dred or more stomachs critically examined would not only make the 

 present bulletin too bulky, but the constant repetition of names would 

 only mislead and bewilder the reader, if indeed any enthusiast would 

 care to read it all. It is better, therefore, to omit the detailed state- 

 ment of the insect remains found in each stomach and give only the 

 general results. 



