198 INSECT TRANSFORMATIONS. 



very extraordinary accuracy, enumerates nearly 2000 

 species of native moths and butterflies; and as the fe- 

 males of these are for the most part very prolific, we 

 have little reason to be surprised at the occasional 

 extent of their depredations. The 2000 species just 

 mentioned are, besides, not more than a fifth of our 

 native insects, most of the grubs and maggots of which 

 are exceedingly voracious and destructive. 



It appears to be indispensable for most insects to feed 

 copiously during their larva state, in order to supply a 

 store of nutriment for their subsequent changes; for 

 many of them eat nothing, and most of them little, after 

 they have been transformed into pupse and perfect in- 

 sects. What is no less wonderful, a corresponding 

 change takes place in the internal formation of their or- 

 gans of digestion. A caterpillar will, as we have seen, 

 devour in a month 60,000 times its own weight of 

 leaves, while the moth or the butterfly into which it is 

 afterwards transformed may not sip a thousandth part 

 of its weight of honey during its whole existence. 

 Now, in the caterpillar, nature has provided a most 

 capacious stomacli, which, indeed, fills a very large 

 portion of its body; but in the butterfly the stomach is 

 diminished to a thread. By a series of minute dis- 

 sections, conducted with great skill, Heroldt traced 

 these changes, as they successively occur, from the 

 caterpillar to tlie butterfly. In the caterpillar he found 

 the gullet, the honey stomach, the true stomach, and 

 the intestines capacious. Two days after its first 

 change all these are visibly diminished, as well as the 

 silk reservoirs, which, in a chrysalis eight days old, 

 have wholly disappeared; Mhile the base of the gulle< 

 is dilated into a crop, and the stomach still more con 

 tractcd into a spindle form. When near its change 

 into the perfect insect the gullet is still more drawn 

 out, while the crop, still small, is now on one side of 



