RELATIONSHIP BETWEEN LARVAL AND IMAGINAL LEGS OF LEPIDOPTERA. 177 
The Relationship between the Larval and Imaginal Legs of 
eee (with Plate). 
By T. A. CHAPMAN, M.D., F.Z.S., F.E.S. 
(Concluded from p. 145.) 
Betore further discussing the general question, we may look at some 
more of the specimens. We may take that represented in plate vi., fig. 2. 
next. Here the amputated larval limb is replaced by an amorphous nodule 
of considerable size. The basal structures seem to be fairly intact, and 
on Gonin’s theory ought to have supplied us with a leg, but the imago 
has no leg at all beyond the trochanter and a round nodule, which 
we may call the femur. I do not know at what date this specimen 
was operated on, but I believe immediately on entering the last moult. 
I always operated immediately after a moult so as to give plenty of 
time for healing to take place before the next moult. In all my 
specimens the trochanter is present in fairly normal condition, showing 
that in amputating the leg I interfered with the femur and all beyond, 
but not with the trochanter and coxa, which are not represented in the 
larval lee. 
In plate vi., fig. 3, the larval parts show that the right leg 
has been interfered with as well as the left. It is regenerated to much 
the same stage as the left lee was in fig 1, and the imaginal 
lee ig correspondingly well dey eloped, though very probably smaller 
than the original leg would have been; but on the left side we have a 
stump that results from injury during the last larval stage, there are 
some remains of the first larval joint, crushed and twisted, and 
attached to it a black mass of dried crust, such as resulted from the 
immediate closing and scabbing of the wound. No regeneration could 
take place during larval life, and what did take place at the pupal 
moult appears to have occurred, not from the base of the leg, but from 
the crushed remains of the first larval jomt. We have in consequence 
a very small representative of the imaginal leg, a complete trochanter, a 
femur half the length of that of the other side, a tibia to a still smaller 
scale, but still showing the tibial spurs, the tarsus cannot be said to 
have more than one joint, but that carries the claws, very small but 
fairly well developed. In this specimen the whole larval injury is 
concentrated on the first joint, the base being uninjured, therefore if 
the imaginal leg originated in this base, independently of the larval 
leg, we ought to have had a limb perfect as to its femur and tibia at 
any rate, even if we choose to accept the view of Gonin that the larval 
lee represents the tarsus. 
In plate vi., fig. 4, we have an instance in which I failed to 
demonstrate the condition of the larval leg, it was, at any rate, much 
damaged and dithicult to recognise, but some minute trace of a cicatrix 
of larval leg probably existed. In the imago we have an example, the 
only one that seems tolerably free from doubt, of a modified trochanter. 
The femur and tibia ave represented by very amorphous pieces, not 
mited in a normal manner, the tibia, however, showing spurs, whilst 
the tarsus is in one piece, with indications of possible division into 
two or three joints and of the terminal hooks. ‘The whole appendage, 
however, is very small and crippled, clearly a yery abortive attempt 
at regeneration, and in no wise a normal, or any way near a normal, 
attempt to produce a limb from the usual centre for its development. 
* Read before the South London Entomological and Natural History Society. 
