398 
Beekeeping 
pickled brood. These diseases weaken colonies by reducing 
the number of emerging bees needed to replace the adult bees 
which die from natural causes. The adult bees are not known 
to be affected. The larva} dead of these diseases show cer¬ 
tain differences in appearance which are useful in determin¬ 
ing which disease is present. These diseases are entirely 
distinct, as shown by these differences in appearance, by 
differences in response to treatment, by differences in 
the age of the larvae affected and by bacteriological ex¬ 
amination. There is no evidence that chilled or starved 
brood develops 
into an infectious 
disease or that 
dead brood favors 
the development 
of an infectious 
disease. 
Fig. 163. — American foul brood : a, 6, /, normal sealed cells; c, j, sunken 
cappings, showing perforation ; g, sunken capping not perforated-; h, l, 
m, n, g, r, larva; affected by disease; e, i, p, s, scales formed from dried- 
down larvae; d, o, pupae affected by disease. Twice natural size. 
American foul brood. 
This disease (Fig. 163) is frequently called simply “foul 
brood.” It usually shows itself in the larva; just about the 
time that they fill the cells and after they have ceased feed¬ 
ing and have begun pupation. At this time the larva is 
sealed over in the comb (Fig. 103, a, b,f). The first outward 
indication of the infection is a slight brownish discoloration 
and the loss of the well-rounded appearance of the normal 
larva (Fig. 163, l). The larva gradually sinks down in the 
cell and becomes darker in color (Fig. 163, h, m) and the 
posterior end lies against the bottom of the cell. Frequently 
