58 
TRANSFORMATIONS OF INSECTS. 
during these changes, the whole internal- lining of the alimentary 
canal also comes away with the skin, as was formerly noticed by 
Swammerdam, and repeatedly observed by ourselves and others. 
The lining of the mouth and gullet, and that of the mandibles, is 
detached with the covering of the head, and that of the large intes- 
tines with the skin of the posterior part of the body ; and besides 
these the lining of the tracheal tubes comes away. The lining of 
the stomach itself, or that portion of the alimentary canal which 
extends from the termination of the oesophagus to the insertion of 
the so-called biliary vessels, is also detached, and becomes 'com- 
pletely disintegrated, and appears to constitute part of the mass 
voided by the insect on assuming its imago state. Herold, how- 
ever, has denied that this change ever occurs in the alimentary 
canal, and says that in the tracheae it takes place only in the 
larger stems. But Swammerdam states that he saw it in the larva 
of the rhinoceros beetle, Oryctes nasicornis , which sheds both the 
lining of the colon and of the delicate as well as larger branches of 
the tracheae ; and Bonnet had witnessed a similar occurrence. 
Burmeister has also seen it, both with respect to the intestine and 
tracheae, in some of the Libellnlce ; and we now add our own 
testimony to the fact of its occurring, not simply at the extremities 
of the canal, but throughout its whole extent, as we have distinctly 
seen during the changes of the nettle butterfly, Vanessa urticce. 
It is more distinctly observed when the larva is changing into the 
pupa state than at any other period, although we believe that it 
really does take place at every change of skin. Hence these 
changes are of the greatest importance to the larvae, which often 
perish during their occurrence. They are undergone by all larvae 
which possess the true organs of locomotion, but it has been 
questioned whether they are common also to the apodal or foot- 
less kinds, more particularly to those which constantly remain in 
the same locality until they have changed into pupae, or nymphs. 
“Reaumur and Huber state that the larva of the common hive- 
bee does not change its skin, but only grows larger. Swammerdam, 
on the contrary, asserts that it does, and also that he has observed 
the same thing in the alimentary canal of the hornet. Burmeister 
believes that it does not take place, and states positively that 
the larvae of Diptera do not moult. We have watched for these 
