PLATE 3 



EXPLANATION OP FIGURES 



13 to 20 are taken from a series of frontal sections of the head of a male nymph 

 with long wing pads, beginning at the frontal surface. The fibrous core is 

 mottled, the nerve cell layer is blank. Obj. 16, oc. 6, table level. 



13 Section through the anterior part of the protocerebral lobes, p.?., showing 

 the lateral ocelli, cc, and the anterior margin of the frontal gland, f.g. 



14 Section showing the connection of the anterior roots, a.r.m.b., and the 

 stalks, m.b.s., of the mushroom bodies. 



15 Section through the central body, c.b., and the central part of the mush- 

 room bodies, m.b. 



16 Section showing the entrance of the central body roots, c.b.r., into the 

 central body. 



