274 SOCIAL LIFE IN THE INSECT WORLD 



Bruchidae seem to be indigenous. At all events, I find 

 them levying tribute from various indigenous plants, wild 

 vegetables which have never tempted the appetite of man. 

 They abound in particular upon the great forest vetch 

 {Lathyrus latifolius), with its magnificent heads of 

 flowers and long handsome pods. The seeds are not 

 large, being indeed smaller than the garden pea ; but 

 eaten to the very skin, as they invariably are, each is 

 sufficient to the needs of its grub. 



We must not fail to note their number. I have counted 

 more than twenty in a single pod, a number unknown in 

 the case of the pea, even in the most prolific varieties. 

 Consequently this superb vetch is in general able to 

 nourish without much loss the family confided to its 

 pod. 



Where the forest vetch is lacking, the Bruchus, none 

 the less, bestows its habitual prodigality of eggs upon 

 another vegetable of similar flavour, but incapable of 

 nourishing all the grubs : for the example, the travelling 

 vetch (Vicia peregrina) or the cultivated vetch (Vicia 

 sativa). The number of eggs remains high even upon 

 insufficient pods, because the original food-plant offered 

 a copious provision, both in the multiplicity and the size 

 of the seeds. If the Bruchus is really a stranger, let us 

 regard the bean as the original food-plant ; if indigenous, 

 the large vetch. 



Sometime in the remote past we received the pea, 

 growing it at first in the prehistoric vegetable garden 

 which already supplied the bean. It was found a better 

 article of diet than the broad bean, which to-day, after 

 such good service, is comparatively neglected. The 

 weevil was of the same opinion as man, and without 



