PROC. ENT. SOC. WASH., VOL. 20, NO. 1, JAN., 1918 13 



abstracts concerning substances or compounds known to be found 

 in, or in connection with, insects were not included, unless they 

 had to deal with an investigation having a direct bearing on 

 entomology. 



An arbitrary classification of the 800 or more titles above 

 mentioned led to the following result: 



per cent 



Honey and beeswax 27.5 



Silk 27.3 



Insecticides 20.4 



Biochemical, Biological and Misc : 15.7 



Well known economic products 9.0 



It will be seen from this list that entomological contributions 

 to Chemistry have, in recent years at least, been made very 

 largely by the insects themselves. 



The greater part of the work referred to concerning Honey and 

 Beeswax was analytical and had to do with the examination of 

 the purity of these substances and with their valuation. 



With Silk, as with honey and beeswax, there was but a small 

 portion of direct interest to the entomologist. A large part of 

 the work concerned the properties of silk in relation to dye stuffs 

 and textiles. 



In the case of Insecticides, as would perhaps be expected, the 

 greater number of investigations dealt with their analytical ex- 

 amination, manufacture, etc. 



The above three groups are not here taken up for detailed dis- 

 cussion, but those interested in any of these subjects will proba- 

 bly find many valuable papers listed in the Index referred to at 

 the beginning of this article. In fact one of the purposes the 

 writer had in mind, in preparing this paper, was to call attention 

 to this useful publication. 



Under the well known products of economic importance were 

 included those to which several references were made. These 

 were nutgalls, cantharidcs, lac and cochineal. As with insecti- 

 cides already mentioned, references in regard to these produc.ls 

 were, for the most part, concerning analytical methods for their 

 examination and commercial valuation. 



Under the list entitled Biochemical, Biological and .Misc. arc 

 included a number of references an examination of which may be 

 not without interest. These included, on the one hand, subjects 

 of peculiar interest to the entomologist, such as the chemical 

 examination of cliitin from insects and concerning which if was to 

 bs expected that considerable work would have been done in (he 

 period covered. On the other hand, one notes unexpected and 



