MII: OEG \ 





lament gnu posited in 



the inner epithelial la\ lamella, 



the two are no longer distinguishable te layers. 



The niesenehymatic layer \\hich envelops rlii-Iia! 



lamella- keep-; p.- with them in their Miperticial , |t 



become., thickened and furnishes the xfroi.ia of the iris with its 

 ahundant non-t riated muscles and blood-vessels (fig. 270 3 ). In 

 .MalMiaU (fig, 1Y.7 | f (1| - ;i time COM' with the 



tunica vascul. .sa. ],. n tj s (/,-), in consequent f uhieh the pupil in 



embryos i.s d.^ed by a thin 



i!ar c 

 membrane. air ady 



stale I. 



Tin- part of the optic cup 

 which i-s ad'acent to the j.iir- 

 ment layer "-,' tho iris and 

 Mil-rounds th-- equator 'f the 

 lens, and which likewise be- 

 to the attenuated mar- 

 ginal zone of the cup (fii_ r . 



FijT- 271. Cross section through the ciliary par 

 -i<> rA'), undergoes an inter- of the eye of an embryo Cat 10 cm. long, after 



Iteration. In O 



Thro.- vsee formed by the fol i 



junction with the neighboring -icmp are shown. vo.ttaie 



layer of connective substance, *** T ^ er 



oil layer of the optic cup; 

 it is convert* d into the ', sheet of connective tissue that has pene- 



of the eye. This pm 



is in the Chick on th" 

 ninth or tenth day < f incubation < Ki: i i i: ). in Man at the end of the 

 uning of the third month ( KOI .I.IKER). The attenuated 



elial do.ible lamella of the cup, in consequence of an especial Iv 

 vigorous growth in area, is laid into D . [n.arly] parallel 



-hor; folds which are arranged radially around the equator of the 

 lens. As in the here, the adjacent mesenchymatic ! 



participates in the growth and penetrates between the folds in the 

 form of tine processes. Across section throui:h the folded part of 

 the optic cup of a Cat embryo 10 cm. long (tig. _7 1 ) aiior U informa- 

 tion concerning the original form of these pro > ! amm tls. 

 It shows that the individual folds are very thin and enclose within 

 them only a very small amount of embr\ (bi 1 ) 

 with line capillaries, and that, unlike the pigment epithelium of the 

 iris, only the outer of the two epithelial layers . tgmented, 



