226 GENERATION 



own, completes the year. And although some of the females in the 

 bee-tribe live sixteen or seventeen months, yet a complete history of 

 them is to be formed in one year. How far the common bee lives 

 longer than one year, I do not know ; if they do, then it is only a con- 

 tinuance or repetition of their last actions of perfection, viz. propagation, 

 and the few months they live longer than the year is only a continua- 

 tion of these acts, which they completely performed within the twelve 

 months. 



Some insects are eggs, maggot, chrysalis and fly in the same season, 

 as the common bee, wasp, hornet, humble-bee, common fly, &c. Others 

 are only egg and maggot in the same season, as the privet-moth, some 

 bees, some wasps which are a chrysalis through the whole winter, and 

 fly the next summer. Others, again, are egg one season, [and are] 

 maggot, insect and fly the next ; as the silk- worm, cockchafer, &c. 



Some insects appear to have three stages of life — the state in the egg, 

 or of the foetus ; the worm-state ; the chrysalis, and the fly-state. It 

 is very probable that all those insects which form what is called the 

 ' nymph,' •' chrysalis,' &c, are of this class. 



I believe the maggot never changes its skin till it is going to form 

 itself into a chrysalis, so that the skin grows with the animal ; and it 

 is probably not of the scarf-skin land, but like the skin of the snail, 

 earthworm, <fcc. 



Caterpillars change their skin several times before they go into the 

 chrysalis state. I believe their skin is to be considered as a kind of 

 cuticle or horn 1 , therefore it does not grow after a certain period. 



Two -fold Birth of Flying Insects. 



Animals of this class have two births, or may be said to have two 

 conceptions; one from the egg, the other from the chrysalis. The 

 exact parts formed in each state are not as yet known 2 . One would 

 naturally suppose that all the vital parts were formed in the first 

 stage, and the wings, limbs, &c. in the second : the first stage brought 

 all the vital parts to their full size ; and as the insect must have an 

 addition of parts, or become another animal, it must lie dormant till 

 such parts are formed. If this had not been the case, then they must 

 have been obliged to change their coats or skin as they grew ; like the 

 lobsters, &c. 



1 [Modern chemistry has shown it to be a peculiar substance called ' chitine.' — 

 Lectures on Invertebrate Animals, 8vo. 1855, p. 349.] 



2 See Herold's ' Entwickelungeschichte des Schmetterlings,' fol. 1835. 



