HYMENOPTERA : CHARACTERS. 379 



leaves of which the young feed. From the nature of their 

 food, and their abode in the midst of it, it will be at once 

 evident that they have little need of locomotive organs 

 serving for its discovery. We accordingly find that the 

 majority of the hymenopterous larvae are footless grubs of 



Bee grubs, natural size and magnified. 



Grub stripped of skin. 



a white colour, and of a fleshy substance, having the parts 

 of the mouth small, and but slightly developed, although in 

 the perfect insect the same organs attain a maximum degree 

 of developement. In those larvae, however, which are ex- 

 ternal feeders, we find the necessity for locomotion causing 

 the addition of locomotive organs ; the legs in the larvae 

 of the saw-flies varying in number from six to twenty-two. 

 The pupae of these insects are inactive, having the various 

 limbs of the perfect insect developed, but inclosed in sepa- 

 rate cases, and lying along the breast. In this respect, 

 therefore, they resemble the 

 Coleoptera, and like them they 

 are in this state either inclosed 

 in cocoons formed by the 

 grubs previous to their trans- 

 Bee pupa. formation, or are naked. 

 The species of this order are extremely numerous. They 

 are annual insects ; the majority of them pass the winter sea - 

 son in the form of grubs or pupa3, whilst others pass this 

 period in the perfect state. These, however, are but few in 

 number, and consist of females which have been impregnated 



