24 BULLETIN OF THE BUSSEY INSTITUTION. 
In December, 1871, I noticed one day in the ‘ potting-house” of 
the horticultural department a small heap of dung that had just been 
brought in from some hen-roost. This dung was firmly frozen, so that 
its several particles were as hard and as little coherent as gravel. Two 
or three days later I happened to see the same heap again, and found 
it alive with maggots. 
A quantity of the dung, together with its inhabitants, was imme- 
diately sent to Mr. F. G. Sanborn, the entomologist, who replied in 
the following terms :— 
Boston, Mass., December 10, 1871. - 
My DEAR Sir, —I have given a close examination to the larve you sent 
me a day or two since. I find them to be the young, or “ maggot,” of a spe- 
cies of fly closely allied to the common “ house fly,” but perhaps belonging to 
the genus Anthomgia, — a set of flies which hover about flowers when winged, 
but which feed in the .larva-form on decaying matter in general. To this 
genus belong the “Onion maggot” so destructive in some sections, and a 
great variety of species more or less injurious to agriculture. The eggs laid 
by the parent fly in early autumn were probably hatched by the increase of 
temperature some months earlier than usual. I shall endeavor to rear the 
creatures to their perfect condition, when I can report still more certainly. 
You are doubtless aware that the difficulty of identifying species from the 
larve alone is very great, so few even of our commoner forms have been 
conscientiously reared. 
Very truly yours, 
Francis G. SANBORN. 
Proressor F. H. Storer, Bussey Institution. 
Mr. Sanborn has since assured me, by word of mouth, that he suc- 
ceeded in rearing perfect flies from the larve in question, and that his 
suspicion as to their injurious character was confirmed. 
He will undoubtedly publish the results of his investigation in due 
season. I allude to the matter merely because of its manifest bearing 
upon the use of those artificial fertilizers which must necessarily, from 
the manner of their preparation, be free from the eggs of insects. 
It is a matter of the commonest observation that the richer kinds 
of dung, such as that of man and of the hog, are liable to be fly- 
blown ; but it seems to be less generally understood that the dungs: 
in question may and do actually serve as hot-beds and nurseries for 
the production of insects which are to be classed among the worst 
enemies of growing crops. 
