This illustration shows the arrangement of the nervous material in the anterior end of an Oligochete Worm, seen in profile. That part of the body wall nearest the observer is supposed to be removed. a, anterior; b.w., body wall; g, dorsal ganglia (brain); g', ventral chain of ganglia; n, nerve ring around the pharynx; o, mouth; p, pharynx.

Oligochete Worm

This illustration shows the arrangement of the nervous material in the anterior end of an Oligochete…