Sargent. — Ojitic Reflex Apparatus. 



PLATE 5. 



Figs. 32-34. Amia calva, 8th day. Three successive sagittal sections of the an- 

 terior portion of tiie niescnccplialon, siiowing tlie optic rctiox cells 

 and tlieir axons uniting vvitliin the inesocoele to form the fibre of Ueiss- 

 ner. Figure .'J'i is median. In tiiese figures anterior is at the right, and 

 dorsal is toward the upper left-hand corner of the plate. X 205. 



Fig. 35. Amia calva, 17tli <lay. Sagittal section of the anterior portion of the 

 mesencephalon, anterior at left. The system of axons within the 

 mesocoele is somewhat more consolidated. X 205. 



Fig. 36. Amia calva, 5tli day. Transverse section through the roof of the mesen- 

 cephalon, cauilad of the posterior conmiissure, showing tlie optic reflex 

 cells. X 100. 



Fig. 37. Amia calva, 5th day. Transverse sectir)ii througli the roof of the mesen- 

 cephalon, and edge of tiie posterior commissure flexure, showing the 

 recessus of mesocoele above tlie posterior commissure. X 87. 



Fig. 38. Amia calva, 8th day. Transverse section through anterior portion of 

 tiie mesencephalon and ]iosterior commissure, anterior to preceding. 

 X 120. 



Fig. 39. Amia calva, 4th day. Sagittal section through the posterior portion of 

 the cord, showing a single posterior canal-cell and its axon. X 1200. 



