34 THE HOUSE FLY—DISEASE CARRIER 
points out that small flies are found at the end of sum¬ 
mer when it has become cooler, and also in the early 
spring, the latter having hatched late the previous au¬ 
tumn. The question of the hibernation of flies will be 
considered in a later paragraph, but in this connection it 
should be stated that Doctor Griffith secured repro¬ 
duction in the late autumn and winter, but that all of 
the resulting flies were of small size, though their lar¬ 
vae were kept at a warm temperature. The flies from 
only one of these batches were of normal size, while 
those in one set were “extremely small, quite pigmies; 
and these died from no apparent cause, probably from 
marasmus, after a month.” He further states that 
from the same batch of eggs he has reared large, me¬ 
dium and small flies. Packard (1874) found that those 
larvae which were reared in too dry manure were 
nearly one-half smaller than those taken from the ma¬ 
nure heap. No direct warmth and the absence of mois¬ 
ture seemed to cause them to become dwarfed. 
The error of deduction made by the famous astron¬ 
omer was by no means an error of observation, as ap¬ 
pears from what precedes, but there are found in houses 
other flies of entirely different species from the house 
fly, as will be shown in another chapter. Some of 
these are considerably smaller, and one of them, the 
little fly often seen on window-panes (Homalomyia 
canicularis ), is very much smaller. In fact, as though 
to perpetuate the error, the Germans call this last spe¬ 
cies “die kleine Stubenfliege”—the little room fly or 
house fly. 
