16 THE HOUSE FLY—DISEASE CARRIER 
pidors and open snuff-boxes. The entomological world 
has accepted the statement, with, however, some doubt 
as to the snuff-boxes. Prof. S. A. Forbes, however, 
informs the writer that August 22, 1889, he received 
from an old friend, T. A. E. Holcomb, then a druggist 
at Kensington, Ill., a box of snuff containing dipterous 
larvae. From these dipterous larvae Professor Forbes 
bred the true house fly. His recollection of the matter 
is very clear, and he has now in his collection a very 
under-sized specimen labeled Masca domestica and 
bearing an old pencil label in his handwriting, “Snuff, 
August 26th.” 
He afterwards called upon Mr. Holcomb in his drug 
store and learned that among his constant customers 
were some old foreigners who came so frequently to 
have their snuff-boxes filled that for convenience in 
serving them he was accustomed to keep an open box 
of snuff upon one of his show-cases, and from this box 
the specimens came. 
A very important series of observations was carried 
on under the direction of Professor Forbes in the sum¬ 
mers of 1908-1909 by his assistants, Mr. A. A. Girault, 
at Urbana, and Mr. J. J. Davis, in Chicago, for the pur¬ 
pose of ascertaining exactly what other substances 
aside from horse manure will serve as breeding places 
for house flies. The results of these observations, not 
previously published, have been placed at the writer’s 
disposal by Professor Forbes. They constitute a very 
valuable addition to our knowledge on this subject. It 
was a surprise to find that nearly a thousand flies had 
