NESTS. 173 



be ranked the dung-rolling and dung-boring beetles, whose 

 proceedings are exemplified by the Geotrupes and Gym- 

 nopleurus, as well as the sexton-beetles ( Necrophorus ), 

 whose exploits in burying small 

 dead animals, in which they de- 

 posit their eggs, are not less 

 indicative of a high degree of 

 instinctive powers. The Cicada 

 likewise, as well as the saw-flies, 

 may also here be noticed, since 

 the care with which the parent 

 constructs a burrow in the stems 

 of plants, for the reception of her eggs, by means of a most ad- 

 mirably constructed apparatus, is equally remarkable, although 

 the larva, as soon as hatched, is compelled to seek elsewhere 

 for its food, namely, the leaves on the adjoining twigs. But 

 the instinct which is exhibited in the selection of appropriate 

 situations for the eggs, and where the larva, when hatched, 

 will find a supply of food, without the same being laid up in 

 store by the parent fly, is found to be possessed by the great- 

 est number of insects. Many species of larvae will feed only 

 upon one particular species of plant ; and the parent fly, in 

 its perfect state, takes no other food than a little honey from 

 every flower which may be in bloom at the time ; still it is 

 only upon that particular plant which suits the taste of her 

 progeny that she deposits her eggs. Here are to be ranked 

 many of the tribes of lepidopterous insects (butterflies and 

 moths). Many species of moths, as well as beetles, reside 

 in the larva state under the bark of trees ; the females, there- 

 fore, by means of a long and jointed ovipositor, are enabled 

 to place their eggs at the bottom of the crevices in the ex- 

 ternal bark. In like manner, the carrion flies deposit their 

 eggs upon carrion ; the flesh-flies upon flesh ; the flies whose 

 larvae feed upon plant-lice, in the midst of the plant-lice ; 



