44 TRANSFORMATIONS OF INSECTS. 
At twelve hours the last thoracic ganglions have united, and at 
eighteen the nerves of the wings have increased in size, and the 
nervous chain in the abdomen has become straight again. At 
METAMORPHOSIS OF THE NERVOUS SYSTEM OF Vanessa urtica. 
9. Forty-eight hours after changing. to. Fifty-eight hours after changing (more highly 
magnified than the previous illustrations). (After Newport.) 
thirty-six hours the optic nerves have grown nearly as large as 
the brain, and the gullet is completely surrounded by an extension 
of the ganglion under it and the brain above. The sixth ganglion 
has disappeared ; and at the end of forty-eight hours the seventh 
is no longer seen, but the thoracic centres increase in size gradually. 
