250 Dr. T. A. Chapman's 



from within, and merely the place where it shall occur, but 

 not the actual rupture, being determined by the hatching- 

 spines. 



It is certainly matter of some interest froin a classi- 

 ficatory point of view, to find the egg and the embryo 

 within it and the method of hatching (hatching spines, 

 etc.), so very nearly identical in Dorypliora dcccmlincata 

 and in Orina tristis. Wheeler's observations especially 

 relate to the development of the embryo ; and as his 

 observations were made entirely on eggs already laid, and 

 ho begins with the egg segmentation preceding the embryo, 

 it is clear that in Doryplwra there is no quasi- viviparity as 

 in 0. tristis. There is, in his paper, no suggestion of the 

 possibility of such a thing. He would certainly have 

 noticed and recorded it had there been any trace of it, 

 although it was not strictly the subject of his paper. 



I believe Doryplwra and Orina are not classified very 

 closely together. It ma}^ be that this method of hatching 

 is common to many s-pecies of Chrysomelids; if so, record 

 of it ought certainly to be more frequent than it is.^ 



Immediately after each of its three subsequent moults, 

 the skin of the larva is quite colourless, exhibiting all its 

 interior anatomy, tracheae, alimentary canal, etc., but it is 

 sufliciently loaded with yellow fat and fluids to make 

 details difficult to observe. It rapidly (in half-an-hour or 

 so) becomes black. At these moults there is no trace of 

 these hatching spines to be noticed. Two circumstances 

 attracted my notice ; one Avas that the larva used inflation 

 to assist the rupture of the effete larva skin. This is not 

 pushed away towards the tail and so stretched in front till 

 it splits as is the method in Lepidoptera, but the whole 

 larva skin is fully on the stretch, and finally slits down the 

 dorsum, the new white larva protruding at once and then 

 creeping out slowly, leaving the empty larval skin slightly 

 contracted., but still looking uncommonly like a living 

 larva, and nowhere with its segments crushed together. 

 It merely takes up the aspect of a younger larva with its 

 subsegmental ridges, when the tension of a full-fed larva 

 within it is withdrawn. 



The larva when neAvly moulted and still colourless is 

 seen to be especially translucent in the thoracic region, 

 and several larger and smaller globules of air are seen to 



^ Mr. Jacobi informs nie that the Colorado beetle is not a Dory- 

 phor&,, but belongs to a genus very neiir to Orina. 



