5°‘ s 
“ Altogether, the refuse from over three hundred ashpits and bins 
(chiefly the former) was examined, and 37 middensteads carefully 
inspected. Human excreta found in the courts and passages were 
also inspected, and breeding-cage experiments with these and the 
excreta of domesticated animals were also conducted. The survey 
was restricted to five areas in different parts of the City embracing, 
in all, visits to 68 streets.* 
“ The result of the investigation and survey has proved eminently 
satisfactory, both from an economic and scientific standpoint. It 
has led to the discovery of the chief breeding places of the fly, and 
many new and interesting facts relating to the food of the larval 
stages have been brought to light ; so that we are now in possession 
of the more important facts relating to the economy of this pest. 
“ The chief breeding places of the house-fly may be classified 
under the following heads : 
“ 1. Middensteads containing horse manure only. 
“ 2. Middensteads containing spent hops. 
“ 3. Ashpits containing fermenting materials. 
“ Leaving for the present the minor breeding places, we may 
proceed to consider the chief ones in detail. 
1. Stable middens containing horse manure only, were broadly 
speaking, found to be the chief breeding places. In the majority of 
these the larval stages of the house-fly occurred in countless 
thousands, revelling in the heat produced by fermentation. The 
adjacent walls often swarmed with newly-hatched flies, and 
occasionally one also found enormous masses of their eggs (fig- 2 )- 
while deep down at the sides, in the cooler portions of the receptacles, 
the pupa or chrysalis stage occurred in enormous numbers, looking 
like small heaps or collections of reddish berries. Middens containing 
a mixture of horse and cow dung were also infected, though to a less 
extent than those receptacles containing horse manure only. It is 
important to note, however, that in all cases where fowls (not ducks 
r geese) were kept and allowed freedom in the yards, relatively few 
of the earlier stages of the house-fly were found; and whenever 
present were invariably located in places inaccessible to the fowls. 
o make ceitain that the fowls were responsible for so remarkable a 
jminution of the fl y larvae and pupae, a trowel full of these was 
treets and also the nature of the receptacles ere here omitted.— R.N’- 
