3l6 Charles R. Stockard 



Sections of perfectly single cydopean eyes 



Fig. 40 Horizontal section through mid-brain showing its corpora bigemina, Cb, and floor of hind 

 brain, Hh, in seventy-seven hour cyclops. 



Fig. 41 \ more ventral section of same series, E, the Cyclopean eye; ol.p., olfactory pits united. 

 Hh, hind-brain and Av., auditory vesicle; Ch, floor of one mid-brain lobe. Guide figure X gives plane 

 of each section. 



Fig. 42 Trans-section of a four day single cyclopean eye in exact ventro-median position, ch, 

 choroid coat; p, pigment spot. 



Fig. 43 Similar section of nine day eye. Humor cavity behind the lens. Note perfectly bilateral 

 brain . p, pigment spot. 



Fig. 44 Section of single median eye below perfectly bilateral brain, thirteen days old. 



Fig. 45 A more anterior section in same series as Fig. 44. The forward tip of the eye ch is seen. 

 A small lens L lies free near the ventral ectoderm; ol.p., olfactory pit; p, pigment spots on anterior end 

 of brain. 



Guide figure j^indicates plane of all sections. 



