IX 



KYK 



liiiilinil 



thai. 



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Illllllllll 



Illllllllll 



O.S. 



FIG. 142. 



pi 



Development of the eye as seen in transverse sections of Fowl embryos. A, Latter half of second 

 day of incubation; B, end of second day ; C, i\ days; D, 3 days; E, latter half of fifth day. 

 ed, External ectoderm ; /, lens; o.r, rudiment of eye; o.s, optic stalk; p.l, pigment layer; 

 r, retina ; thai, wall of thalamencephalon. [The gap below the lens in D is due to the section passing 

 through part of the choroid fissure. Each division of the scales represents -01 mm.] 



