248 HOUSE, GARDEN, AND FIELD 



must be able to feed for some days at least. It would 

 never do for her to depend upon the coarse vegetable food 

 on which she subsisted as a larva. That would weight 

 her body and interfere with her flight, besides taking 

 up too much of her time. The sweet and nutritious 

 juices of flowers are much more suitable. They can be 

 sipped rapidly, and the weight is insignificant. Change 

 of food brings with it a change of mouth-parts ; the insect 

 discards the biting jaws of the caterpillar, and acquires 

 a new sucking proboscis. The sucking proboscis leads 

 to yet further complications, for there will be an interval 

 during which the old mouth-parts are out of gear, while 

 the new ones are not quite ready for use. Change of food 

 leads therefore to a resting-stage. 



But among the moths and other winged insects we 

 find one here and there which does not require to scatter 

 its eggs widely, and such insects as these sometimes lose 

 their wings altogether. The female vapour er-moth is a 

 well-known example. Here the caterpillar is not at all 

 particular about its food ; the leaves of most garden 

 shrubs and trees suit its taste ; moreover this caterpillar 

 can run about very well. In this case, therefore, all the 

 eggs may be safely laid in one place, and the female need 

 not fly at all. Evidently her ancestors used to fly, for 

 the stumps of wings can still be discerned on her back. 

 The male vapourer flies very well, and both male and 

 female still go through their resting-stage. 



THE SIZE OF INSECTS. 



Insects are small animals. A very large beetle may 

 measure four and a half inches in length, but this includes 

 a long horn. One of the longest stick-insects (so called 

 because the body and legs resemble dry sticks) may be 

 nearly a foot long, but the weight of such an insect is by 

 no means great. Some dragon-flies are about six inches 

 long, and there are some moths whose wings can expand 

 to about a foot. None of these relatively enormous 



