Hypermetamorphosis 



the conviction, if we had not witnessed the 

 first moments of the tertiary larva, that it is 

 absolutely impossible for the creature to turn 

 right round. 



And now see to what curious inferences 

 this lack of observations made at the due 

 moment may lead us. We collect some 

 pseudochrysalids and heap them in a glass 

 jar in all possible positions. The favour- 

 able season arrives; and with very legitimate 

 astonishment we find that, in a large num- 

 ber of shells, the larva or nymph occupies 

 an inverted position, that is to say, the 

 head is turned towards the anal extremity 

 of the shell. In vain we watch these re- 

 versed bodies for any indications of move- 

 ment; in vain we place the shells in every 

 imaginable position, to see if the creature will 

 turn round; in vain, once more, we ask our- 

 selves where the free space is which this 

 turning would demand. The illusion is 

 complete: I have been taken in by it my- 

 self; and for two years I indulged in the 

 wildest conjectures to account for this lack 

 of correspondence between the shell and its 

 contents, to explain, in short, a fact which 

 is inexplicable once the propitious moment 

 has passed. 



On the natural site, in the cells of the 

 125 



