44 



IKANSFORMATIONS 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 ItrhCCC. 



9. Forty-eight hours after changing. 10. Fifty-eight hours after changing (more highly 

 magnified than the previous iUustrations). (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 

 4s no longer seen, but the thoracic centres increase in size gradually. 



