CHAPTER III. 
THE METAMORPHOSES OF THE NERVOUS SYSTEM. 
NOTHING can be more striking at first sight than the difference 
between the nervous apparatus of the larva, of the bee, for instance, 
and that of the perfect insect ; or between that of the larva of the 
water-beetle and the mature Dytiscus. But a careful examination 
of the anatomy of the nervous masses, and of the conducting cord 
between them, will tend to show that there is not a perfect altera- 
tion in their arrangement before and after metamorphosis. There 
is great modification, but the original design never loses its im- 
pression, through all the eccentricities of growth, upon the struc- 
tures of the nervous system of the most elaborately-formed perfect 
insect. We have seen that the segments of the -larva become 
apparently less numerous in the imago or perfect insect, and it has 
been stated that the diminution of the number of these important 
body-rings is brought about by their coalescence. Now, there is 
a remarkable relation between the segments of the body of the 
articulate animal and the disposition of its nervous structures, and 
it will be noticed that as the segments coalesce,- so do also por- 
tions of those \vonderful parts which enable the will to be exer- 
cised, instinct to be made manifest, and the senses to be enjoyed. 
The nervous masses coalesce in order to become more perfect 
in their functions ; they concentrate their influence and make the 
insect less vegetative and more intelligent. The feeble nerves of 
many larvae are remarkable when the activity and importance of 
those of the perfectly developed insect are considered ; there 
is an evident relation between the wants of the animal and its 
gifts, and these are showered down according to that wonderful 
