138 SOCIAL LIFE IN THE INSECT WORLD 



not follow the example of the swallows, each of whom 

 brings a fair share of the straw and mortar for the 

 building of the nest and the midges for the young 

 brood ? No, he does nothing ; perhaps alleging the 

 excuse of his relative weakness. But this is a poor 

 excuse ; for to cut out little circles from a leaf, to rake 

 a little cotton from a downy plant, or to gather a little 

 mortar from a muddy spot, would hardly be a task 

 beyond his powers. He might very well collaborate, 

 at least as labourer ; he could at least gather together 

 the materials for the more intelligent mother to place 

 in position. The true motive of his idleness is 

 ineptitude. 



It is a curious thing that the Hymenoptera, the 

 most skilful of all industrial insects, know nothing of 

 paternal labour. The male of the genus, in whom 

 we should expect the requirements of the young to 

 develop the highest aptitudes, is as useless as a 

 butterfly, whose family costs so little to establish. The 

 actual distribution of instinct upsets our most reason- 

 able previsions. 



It upsets our expectations so completely that we 

 are surprised to find in the dung-beetle the noble 

 prerogative which is lacking in the bee tribe. The 

 mates of several species of dung-beetle keep house 

 together and know the worth of mutual labour. Con- 

 sider the male and female Geotrupes, which prepare 

 together the patrimony of their larvae ; in their case 

 the father assists his companion with the pressure of 

 his robust body in the manufacture of their balls of 

 compressed nutriment. These domestic habits are 

 astonishing amidst the general isolation. 



