180 PATIEN. [VoL. Il. 
EXPLANATION OF PLATE VIII. 
Fics. 8 AND 8a. Ventral and side view of head just after rupture of embryonic 
membranes. x 86. 
Fic. 9. Side view of head of an embryo almost ready to hatch. Semi-transparent. 
X 96. 
Fics. 10 AXD Ioa. Dorsal and side view of the head of a full-grown larva. 
Fics. 11-16. Surface views of the dorsal, anterior edge of the optic plate, show- 
ing successive stages in the formation of the first eye. In order to economize time 
and labor, the surface nuclei are shown only in Figs. 14 and 16. X 260. 
Fic. 17. Semi-diagrammatic and transparent side view of eye I., in the stage 
shown in surface view in Fig. 16. 
Fic. 18. The same, in a later stage, showing the bend in the middle of the sensi- 
tive area, to form the vertical and horizontal retinas, and the sense organs and nerves 
to each part. 
