5() [ March, 



possessed any hooks. In several instances the thoracic legs were 

 normal, in others possessed thickenings and projections of their basal 

 joints. 



The labrum and mandibles are those of a normal larva and the 

 labium is but slightly altered in most instances. The maxilla is more 

 or less altered in all, in some there is quite a short haustellum present, 

 in others the base is merely thickened ; in two this is the case, with 

 the two normal palpal processes much lengthened. In all cases the 

 antenna is most altered, the basal joint is large and bladder-like, whilst 

 the remainder is from 1 to 3 or more mm. in length, in one considerably 

 longer, folded together as the pupa! antenna is, within the larval head, 

 before moulting it becomes brown and transversely ribbed, just like 

 the pupal antenna, but has a white soft terminal joint with a terminal 

 bristle. The head is, in one or two, enlarged proportionally to the 

 extra moult, in others is rather smaller, but being in most distorted by 

 the non-moulting of the larval skin, cannot really be definitely described, 

 except that it is broadly the ordinary larval head. The eyes are, 

 however, more or less altered. In nearly all the six eye-spots can be 

 observed, but the two upper are usually smaller or disappearing. They 

 have amongst them yellow, raised, clearly defined patches, which I do 

 not understand. In several of the larvae is a crescentic slightly raised 

 mark lying between the eye-spots and the base of the antenna ; this is 

 clearly the crescentic mark of the " glazed eye," both from its form 

 and from its position, the latter not at first recognisable, until it is 

 remembered that the face becomes bent forwards in the pupa, and 

 that the antenna is thrown backwards. 



Though possessing normal jaws, which they could move freely, 

 none of these larvae made any attempt to eat, so that they were clearly 

 in a different condition from the one larva of my former experiment, 

 which I did not examine carefully, but which seemed to be a normally 

 organized larva. These, on the contrary, partake to a great extent of 

 pupal characters, chiefly in the change in the antennae, also in the 

 maxillae, to some degree in the thoracic legs, in the want of crotchets 

 to the prolegs, and most interestingly in the eye changes. I think 

 they show^ clearly that the crescent of glazed eye is an appendage to 

 the eye, but is not in any way a part of the eye itself, since it is dis- 

 tinctly separate from the larval eyes, just as in the pupa, it is outside 

 the area which often shows indication of the hexagons of the imaginal 

 eye, and beneath which that commences its development. 



The two experiments show that there is either in different races 

 of comes a different amouut of resistance to such changes, or that 



