IN MYRIAPODA AND INSECTA. 
291 
legs on the left side had been cut close off, but the basilar joints in these were elongated, 
and the insect cast its skin without difficulty. In the fifth specimen, which cast its 
skin during the very moment I was examining it, the facts were still more satisfac- 
tory. The middle leg on the left side had been removed, but the basilar joint, as in 
the other instances, had become elongated. Besides this, a portion of the posterior 
leg on the same side had been removed at the tibial joint, and this had now been re- 
produced with the tarsus and claw. It now formed a short leg, very obtuse at its 
extremity, with the minute black claw sunk in its apex. This fact sufficiently proved 
to me that a power of reproduction exists in insects which undergo a complete meta- 
morphosis, as well as in those which do not change their form, and it led me to watch 
with greater assiduity the passing of these individuals into the pupa state. 
At the expiration of nine days from the commencement of the experiments (June 
1st), one of the larvse, that was nearly full-grown when operated on, suspended itself 
to enter the pupa state. At that time there were only seventeen specimens still living 
out of the twenty-eight originally employed, and four of these died soon after. There 
then remained two of the oldest, six of the next age, and, as above stated, five of the 
youngest. The eight oldest specimens had all changed to pupae by the 5th of June ; 
but the remaining five continued to feed until the 6th, between which and the 9th, 
the seventeenth day after the operation, these also had become pupae. I was now 
much gratified to find that most of them gave distinct evidence of reproduction having 
taken place. In some of them the tibial and tarsal portions of the legs had been re- 
stored ; in others entire limbs had been reproduced (fig. b.f. g.), while in two or three 
instances the experiment appeared to have entirely failed. I waited, therefore, with 
much eagerness for the development of the perfect insects. 
The first specimen came forth early on the morning of the 14th of June, the 
twenty-second of the experiment, having remained in the pupa state only eleven 
days and seventeen hours, during which the temperature had ranged from 61°Fahr., 
at which it entered the pupa state, to 76° Fahr., being 71° Fahr. at the time the in- 
sect came forth ; from that time to the 17th of June, the twenty-fifth of the experi- 
ment, eight perfect insects made their appearance. The longest period that any of 
them remained in the pupa state was eleven days seventeen hours, and the shortest 
ten days fourteen hours; thus most directly proving the influence of increased tem- 
perature in hastening development ; the usual length of time which this insect re- 
mains in the pupa state, at a medium temperature of 60° Fahr., being fourteen days. 
In two of these specimens no reproduction of the limbs had taken place, but in the 
six remaining ones the reproduction was complete. In one specimen (fig. 6.) the 
entire intermediate limb had been reproduced (g), but it was much smaller than the 
other limbs. In the other specimens the tibial and tarsal joints had been restored, 
and always the minute claw. In some instances the tarsal joints were very short, 
but their number and relative proportions were usually maintained, while in others 
the tibia was developed to its full extent, but without its articular spines (fig. 6 to 13.), 
