48 
Psyche 
[March 
the beetle larva, yet, with little used books, which are kept un- 
disturbed in darkness, or with rare books of leather and hand- 
made paper, there remains the possibility of an approximation 
here of the extensive injury caused in tropic libraries. 
Three living larvae and two adults, either dormant or dead, 
with hand-made paper for food, were placed in a glass vial which 
was subsequently corked. The vial was then placed in a desk 
drawer. Observations were made from time to time and they 
yielded several interesting results. A few days after these insects 
were confined as described above, it was noted that there were 
but two larvae. A careful examination revealed a few particles 
of the other larva, which had evidently been eaten by the sur- 
viving two. Unfortunately, it can not be stated whether or not 
the larva was killed by its companions or died from some other 
cause before its body was used for food. It was noted, at the 
same time, that these two larvae had begun to consume the adult 
beetles as well. During a period of a week, the interiors of the 
two bodies were exhausted and thereafter the external, chitinized 
portions were broken into small fragments. It was impossible 
to ascertain whether or not these bits of the chitinized parts 
were actually eaten, but they were finally reduced, on the whole, 
to rather small particles. When the larvae were finished with the 
remains of the adults, they both ate into the cork stopper. One 
larva, which mined on the surface, produced a furrow 11 mm. 
long and about as wide as its body, or 1 mm., while the other 
commenced a mine obliquely leading into the heart of the cork. 
After an absence of observation for ten days, it was found that 
but one larva was present. The inference is that this suvivor 
had eaten the other. This remaining larva continued to mine 
into the cork for a depth of 9 mm. and then turned about and 
widened the mouth of the boring. This total activity took three 
weeks time after which, the grub crawled out upon the hand- 
made paper and seemed as vigorous as ever although it had been 
bottled over five weeks. It is worthy of mention that the hand- 
made paper was not eaten, and that protein and cork were pre- 
ferred, apparently. 
The cannibalistic habit of the larvae, if at all general, would 
adequately account for the surprisingly few insects found in the 
