THE METAMORPHOSES OF THE NERVOUS SYSTEM. 
41 
least and the most tardily. The butterfly, once escaped from 
its chrysalis case, is found to have undergone extraordinary 
alterations in the nervous system. The abdominal chain of 
ganglions appears to be formed of four masses only ; the nervous 
centres of the first two segments of the abdomen of the caterpillar 
state have disappeared by uniting with the enlargement in the 
metathorax ; and those of the last four rings have become 
concentrated into one mass. 
Newport has given us the results of his study of the progressive 
LARVA and pup^e OF Vanessa urticce. 
The larva just suspended ; three stages of chrysalis development ; the larva-skin gradually 
separating. 
changes in the nervous system of the small tortoiseshell butterfly 
( Vanessa urticce ), and his history of the structural alterations 
that take place hour after hour is certainly most remarkable. 
This butterfly undergoes its changes in fourteen days, and the 
caterpillar suspends itself to undergo its transformation into the 
pupa or chrysalis. “ Two hours,” writes this excellent observer, 
“ after the larva of Vanessa urticce has suspended itself to undergo 
its transformation, and in which state it remains from six, eight, 
ten, or even twenty-four hours — according to the strength of 
the individual and other circumstances — before it throws off its 
last larva skin, a considerable alteration has already taken place 
in the body of the larva. The ganglions in the head are still 
