114 INSECT LIFE vm 



but then they do not expand, remaining ahvays 

 crumpled, while, when the large piece of which the 

 sheaths are a part is pushed back by the move- 

 ments of the abdomen, they may be seen issuing 

 gradually from the sheaths, and immediately they 

 gain freedom, assuming dimensions out of all propor- 

 tion to the narrow prison from which they emerge. 

 They are then the seat of an abundant influx of 

 vital juices which swell and spread them out, and 

 the turgescence thus induced must be the chief 

 cause of their coming out of their sheaths. When 

 freshly expanded the wings are heavy, full of 

 moisture, and of a very light straw colour. If the 

 influx should take place in an irregular manner, the 

 point of the wing is seen to be weighed dovv^n by a 

 yellow droplet contained between its under and 

 upper surface. 



After denuding itself of the abdominal sheath, 

 which draws away with it the wing-cases, the Sphex 

 again is motionless for about three days. During 

 this interval the wings assume their normal colour- 

 ing, the tarsi take colour also, and the mouth-parts, 

 at first spread out, assume their normal posi- 

 tion. After twenty-four days as a nymph the insect 

 attains its perfect state, tears its imprisoning cocoon, 

 opens a way through the sand, and appears one fine 

 morning in the light as yet unknown to it. Bathed 

 in sunshine, it brushes wings and antennae, passes its 

 feet again and again over its abdomen, washes its 

 eyes with its forefeet moistened with saliva, like a 

 cat, and, its toilette made, flies joyfully away. Two 

 months of life are before it. 



Beauteous Sphegidae, hatched under my eyes 



