Diagrams 1—10. Based on several series of adult female brains. Not drawn to a scale, but approximately accurate. ©, central; cg, cell 
group; el, common post-lateral; cp, post-central; cpc, common post-central; g, giant cells; Z, lateral; Zc, large cell group; m, median; pt, precen- 
tral; pl, post-lateral; ptc, posterior; /, optic nerves; 2, oculomotor nerves; 3, antennal nerves; 4, oesophageal nerves. 
