PLATE 4 



EXPLANATION OF FIGURES 



17 Section through the posterior part of the central body, showing the origin 

 of the posterior roots of the mushroom bodies, ■p.r.m.h. 



18 Section showing the posterior dorsal commissure, p.cm. The exit of the 

 labrofrontal nerve, l.f.n., from the nerve cell layer is also shown. 



19 Section showing the entrance of the ocellar nerves, oc.n., and of the fon- 

 tanel nerve, /.n., into the protocerebral fibrous core. The large lobes of the 

 posterior roots of the mushroom bodies, p.r.m.h., are very prominent, and are 

 also connected with the protocerebral fibrous core. 



20 Section showing the connection between the protocerebrum, deutocere- 

 brum, and tritocerebrum. 



