256 MILDRED HOGE RICHARDS AND ESTHER V. FURROW. 



PLATE II. 



FIG. i. Details of the three ganglia (Transverse section of head). X 495 (4 

 mm. obj., 10 ocular). 



FIG. 2. Transverse section of head of fly with small eyes. Same magnification 

 as Plate i, Fig. i. 



FIG. 3. Transverse section of totally eyeless fly. Same magnification as Fig. 

 2. 



