512 
“ Reference has already been made to the more important 
materials in which the larvae were found breeding, but no details 
have been given as to the exact nature of their food. The dietary, 
so far as one has been able to see, is almost exclusively that of moist 
decaying vegetable matter. Horse manure and spent hops were most 
favoured; but they, revelled also in rotten flock beds, straw 
mattresses ; they thrived on old cotton garments and rotten sacks, 
and waste paper ; and seemed especially partial to the dirty beddings 
from rabbits and guinea pigs. T hey fed also on bread, decayed fruits 
and vegetables, the excreta of domestic fowls and pigs, and on human 
excreta in the ashpits and stable middens. In all cases, however, they 
thrived best and occurred in the greatest profusion where fermenta¬ 
tion had taken place, so that the temperature of the habitat was 
raised above that of the outside air. 
Like nearly all its congeners, the house-fly undergoes a complete 
metamorphosis, in which there are four well-marked stages; these 
stages in the life cycle are : — 
1. The egg (ovum), commonly' known as ‘fly-blows.’ 
2. 1 he larva or maggot stage. 
* 3 - Lhe pupa or chrysalis stage. 
4 - The imago, or perfect fly. (The final stage.) 
1 st Stage. The eggs are laid in small irregular clusters, or in 
arge collective masses* (figs, i, 2) consisting of many thousands of 
1 mdual eggs. They are almost invariably deposited on or in such 
stances as will provide food for the larvae or maggots. They are 
., 3 y P ^, Cec ^ ‘ n narrow cr evices near the surface, but, occasionally, 
r 3 •stance of from four to six inches below the surface, the 
r f . s P 0/s cases being fermenting vegetable matter or the 
likelv t '^mediately over such materials, or in refuse that is 
do not f Crment ' * he y are often laid, however, on materials which 
» “ - - 
due to the delr^ Wh ' te ’ and P resent a highly polished surface, 
form of the ' VISC ° aS su stanc e with which they are coated. The 
—___ggjnay e seen on referring to the micro-photographs 
returned 8 nS ^ Packed* ,he * r 'BS* >" one small area. 
.t,a 1 n to the same snnf r ' ''hen disturbed they flew awav, but 
- -poi m a few minutes.—K. X. 
