72 



HALF HOimS WITH INSECTS. [Packakd. 



The Swedish Count Degeer, ia 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 Avithout 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 Avithin 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. 



Keduvius, 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 Eeduvius (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, 



