IN MYRIAPODA AND INSECTA. 
285 
cells, but remain coiled up until their new covering- has acquired strength and conso- 
lidation. When the specimens that had been deprived of their antennae again made 
their appearance, I found that the experiment had been entirely successful. Each 
individual now had its antenna and legs reproduced ; but the new parts were much 
shorter and smaller, and of a more delicate colour, than the uninjured corresponding- 
parts in the same animal. The new antenna was but little more than one-half the 
length of the original one, and was very rarely used for touching and exploring ob- 
jects, but seemed to be carefully preserved by the animal from coming into contact 
with anything. In two of the individuals the new organ had but six joints (Plate XIV. 
figs. 1 and 2.), but in these instances nearly the whole organ had been reproduced, 
having been cut off close to the basal joint (a). In the other instance the new an- 
tenna had seven joints, like the original one, but in this case the antenna had been 
divided, and reproduction commenced in the middle of the third basal joint (fig. 3. b). 
The joints of the new antennse were much thicker in proportion to their length than 
in the perfect organ. They were thickest at each extremity, each joint resembling a 
figure of eight, or an elongated hour-glass. The apical joint of the antenna was very 
minute, and sunk into the preceding one. Each joint was encircled with hairs at its 
distal extremity, while the joints of the original antennse had only a few scattered 
hairs on their under surface. In addition to this, the articulations of the new joints 
were less perfect than in the old, the intussusceptions or reduplications of the tegu- 
ment forming the articulations being exceedingly slight. 
There was one circumstance in connexion with these reproductions that seems espe- 
cially worthy of notice. In the antenna (fig. 3.) that had been divided in the middle of the 
third basal joint, the junction of the new with the original part of the organ was clearly 
indicated by a marked difference of colour in the two portions of that joint, in which 
the reproduction commenced. Thus it was not the whole organ that was reproduced, 
in this instance, but only so many joints of it as were deficient, — part of the third, the 
fourth, fifth, sixth and seventh. It does not appear necessary, therefore, that, when one 
part has been lost, the entire organ must be removed before reproduction can take place, 
as is believed to be the case with the limbs of Crustacea ; but reparation begins in the 
part in which the injury occurs, and the new structures produced are only sufficient to 
replace those which have been removed. In the other two instances of reproduction of 
the antennse, the reparation commenced at the articulation of the first basal joint with 
the second (fig. 1. a), the basal joint of the original organ being left attached to the 
head in each experiment. In these two instances, as already stated, there were only 
six joints to the new antennse. This deficiency I am inclined to attribute to the cir- 
cumstance that the individuals had very nearly approached the time when the power 
of reproducing parts of their own bodies had greatly decreased, and would soon alto- 
gether cease, as was shown in the circumstance, that they had so nearly reached their 
adult state, that each acquired only one new segment to its body at this change of 
tegument, the next change of which would perhaps have been the last. 
