DISSECTED MODEL OF AN INSECT S BRAIN. 



155 



cap-like portion, distinguished by horizontal lines (c). These are the 

 portions which should be borne in mind in passing through the series. 



Os 



CL—&- 



'i rrvb 



FIG. 3. — Diagrammatic) outlines of sections of the upper part of the 

 brain of a Cockroach. Only one side of the brain is here represented. The 

 numbers indicate the position in the series of 34 sections into which this 

 brain was cut. inb, mushroom-bodies, with their cellular covering, c, and 

 their stems, st; a, anterior nervous mass; m, median nervous mass. 



