RESEMBLANCES AMONG ANIMALS. 71 
cealed. One of the uses of the phosphorescence with 
which many insects are furnished, is probably to 
. frighten away their enemies; for Kirby and Spence 
state that a ground beetle (Carabus) has been observed 
running round and round a luminous centipede as if 
afraid to attack it. An immense number of insects 
have stings, and some stingless ants of the genus Poly- 
rachis are armed with strong and sharp spines on the 
back, which must render them unpalatable to many of 
the smaller insectivorous birds. Many beetles of the 
family Curculionidee have the wing cases and other ex- 
ternal parts so excessively hard, that they cannot be 
pinned without first drillmg a hole to receive the pin, 
and it is probable that all such find a protection in 
this excessive hardness. Great numbers of insects hide 
themselves among the petals of flowers, or in the cracks 
of bark and timber; and finally, extensive groups and 
even whole orders have a more or less powerful and 
disgusting smell and taste, which they either possess 
permanently, or can emit at pleasure. The attitudes of 
some insects may also protect them, as the habit of 
turning up the tail by the harmless rove-beetles (Sta- 
phylindidz) no doubt leads other animals besides chil- 
dren to the belief that they can sting. The curious 
attitude assumed by sphinx caterpillars is probably a 
safeguard, as well as the blood-red tentacles which 
can suddenly be thrown out from the neck, by the 
caterpillars of all the true swallow-tailed butterflies. — 
It is among the groups that possess some of these 
varied kinds of protection in a high degree, that we 
