72 
HALF IIOUHS WITH INSECTS. [Packard. 
The Swedish Count Degeer, in his classic Memoires , pub¬ 
lished a century ago, says that he kept full sized individ¬ 
uals in a sealed bottle for more than a year without food. 
Dr. Landois has recently ascertained how these insects are 
enabled to fast so long. He observed that, as in the flea 
and louse, the blood drawn in from their victims, collecting 
in the small intestine, loses its cells and forms a blackish 
mass, which remains for months unaltered. “Thus after 
the bug has fully gorged itself, it has within its small intes¬ 
tine a reservoir on which it may live a long time.” 
But happily, though few may be aware of it, the bed-bug 
has a natural enemy, the cockroach, whose “mission” it 
fig. 56. 
Fig. 57. 
Reduvius, pupa and young. 
seems to be to keep this and other insects in check. What, 
then, if the cockroach nibbles our towels and clothes occa¬ 
sionally when driven through stress of hunger? The cock¬ 
roach is particularly valuable on ship-board by reason of 
its insectivorous habits. The Reduvius (Fig. 56, pupa) 
is also said to prey upon the bed-bug. Degeer tells us 
that the wingless young (Fig. 57) have the instinct to en¬ 
velop themselves in a thick coating of particles of dust, and 
“so completely,” adds Westwood, “do they exercise this 
habit that a specimen shut up by M. Brulle, and which had 
undergone one of its moultings during its imprisonment, 
