144 THE ENTOMOLOGIST S RECORD. 
position, that no part of the imaginal leg existed, or was represented, 
in the larval leg, except, perhaps, the tarsus. 
My position is to assert the older idea, that the three parts or 
joints of the larval leg are femur, tibia, and tarsus, and that these 
parts of the imaginal leg originate in those larval sections. And I 
expected to find that a leg regenerated, which ought by Gonin’s 
hypothesis to be, as regards the femur and tibia, the normal leg of the 
imago, would not be so. Newport’s experiments, I think, suffice to 
show that my view of Gonin’s position is correct, but one always likes 
to verify these matters one’s self. The few experiments I made last 
year on this subject, were really made rather with a view to finding 
out how to attack it than with any hope of a definite result. They do, 
however, present enough material to yield some definite results, con- 
firmatory of the hypotheses I have adopted, and, I think, negativing 
that upheld by Gonin. 
The question is complicated by the many interesting facts of 
regeneration, which would well repay further more accurate experi- 
ments, and it is rather in their bearings on that side of the subject 
than on that before us, that my experiments must appear so meagre 
and inconclusive. 
My experiments consisted in removing the whole or portions of the 
third left lee of certain larve. Those I used were Porthetria dispar 
and Saturnia pavonia (carpint). The latter are stillin pupa. The results 
I lay before you are only those of the former species. I selected these two 
species merely because I had an abundance of eggs of each. I 
removed only one leg (though sometimes I fear injuring others, 
through the struggling of the larva), as interfering less with the health 
and progress of the larve. One leg also enabled a comparison to be 
made with the leg of the opposite side. I selected the third lege 
because it is hidden in the pupa beneath the wing, and so would not 
leave an abnormal vacancy on the pupal surface, which is often fatal 
in pupal existence. ; 
I began by chloroforming my larva, with a view to proper 
humanity, but found that chloroform inflicted much greater incon- 
venience on the larva than to hold it firmly in the fingers and snip 
off the limb. The inconvenience this caused both at the time and 
afterwards was much less than I anticipated. I imagine that no 
actual pain is felt in our meaning of that word. Newport gives some 
details of the effects of the operation on the health of the larva and 
the healing of the wounds. ‘The preparations I show you are the two 
third legs of the imagines, and the same portions of the larval skin 
found with the pupa. The larval skin of Porthetria dispar does not 
shrivel up very much at the pupal moult, so that by soaking it in 
ammonia for some time I have been able to unrayel it to some degree, 
and in a few instances with very fair success. 
The specimens will, to a great extent, explain themselves. That 
represented in pl. vi., fig. 1 may be taken first. On the right side 
(left as mounted) of the insect, the larval and imaginal lees are 
normal. On the left the larval leg is a mere stump, but examination 
shows that it possesses all the parts of a complete larval leg, three 
joints and a claw. In this case the leg was removed in an earlier 
skin, removed to its base, and we here have in the last larval skin a 
regenerated leg, though of very small size. The parts are all there, 
