40 Proceedings of the 



change of skin ; they are small short wings after the second 

 change, and expand into their full size after the third and 

 last. In the same way the alteration in the proportions and 

 in the antennae are gradual and progressive, and may be 

 traced as the animal moults. Another circumstance which I 

 must not overlook, although at first sight it seems to make 

 against me, is, that in the young insect (that is, the insect ex- 

 cluded from the egg but not yet furnished with wings), the male 

 and female sexual organs are not developed, or at least not 

 fully developed ; while in insects passing through what is called 

 a perfect metamorphosis, they are as fully developed on emerg- 

 ing from the chrysalis as ever they are. But I would only 

 class this with the other instances of growth, and rather use 

 the analogy of the changes in our own species on attaining to 

 puberty, to show that it is not an essential ingredient in meta- 

 morphic changes. Such changes are obviously not only of 

 much less importance, but also of a totally different class of 

 physiological development, than the change effected in the 

 dormant chrysalis, and, it appears to me, are to be looked at as 

 instances of growth in the perfect insect, not as a mode of me- 

 tamorphosis at all. 



In leaving this part of the subject, I have only farther to 

 say, that I am quite alive to the meagreness of the obser- 

 vations on which I have ventured to build this hypothesis, 

 and that my premises might have been more extended. Had 

 I had more eggs, and had the opportunity of opening them at 

 different periods, my premises would have been more extend- 

 ed. But as long as there was the chance of a leaf-insect being 

 hatched from the eggs, they were too valuable to be broken. I 

 have only examined one addle egg, and it chanced to be one with 

 what I suppose to be the chrysalis in it. Some more fortunate 

 individual will, I hope, ere long have the opportunity of settling 

 the question ; and if, on opening eggs at an early period, he find 

 a maggot, and at later periods this capsule, I think I shall then 

 be entitled to say that it has been settled in my favour. 



But to proceed with the history of the insect. After hav- 

 ing reached the form of a six-legged jointed insect, it emerges 

 from the egg by pushing off the lid. It comes out middle 



