The Biology of the Roach 73 
and only 16 were left uncovered. It is only reasonable 
to surmise that the unnatural conditions of their life at 
this time and my frequent interruptions may have hin- 
dered the normal functioning of some of the mothers in 
so delicate a task as this, and while the mothers in con- 
finement concealed only 82 per cent of the egg cases, 
in their own environment and undisturbed, they would 
show a greater per cent of efficiency. As suggested 
above, if the egg cases had been dropped by mere chance, 
by far the greater part of them would have been on the 
floor of the jars. In many cases they were found 
crammed into crevices that must have been really dif- 
ficult of access, and in more than one instance, three or 
four lay end to end in the same cranny in the bark, 
when nooks were scarce. In some cases we know posi- 
tively that the mud must have been carried at least three 
inches. 
I repeat the assertion that the act of plastering the 
egg cases must be deliberately done. While these 
mothers were never caught in the act of this work, we 
have the interesting details of this behavior of an allied 
Species, Periplaneta americana Linn., by V. R. Haber.” 
He says that at 2:50 a. m., the female began to scar and 
roughen the surface of a cardboard in the cage. She 
chewed and munched at the upper surface of the paste- 
board until she had made quite an appreciable dent, not 
dropping the pasteboard on the bottom of the cage, but 
mixing the bits with a secretion from the mouth until all 
became a damp mass. At 3:30, she crawled forward over 
the scar with her abdomen bent anteriorly and ventral- 
ward, probing about with the protruding dotheca until 
she located the sear which she had just made. After sev-_ 
eral unsuccessful attempts at placing the egg case in the 
10Ent. News 31:190-193. 1920. 
