CHORIO-ALLANTOIC GRAFTS. 



287 



of the eye are typical of the normal of the same age. The ciliary 

 processes show around the lens. This case, 9 .4 I, is therefore 

 selected for detailed de-< -notion. 



Alt 



O.Se 



A.C.- 



p Alt 



Oh. 



I- 1-.. -. Cl n from thir ur primonliiun. 



.1 i. (X ao.) 



i ... .:. .liranc. Ch.. : mem- 



.li.irv proc St., ora serrata. P..\:;.. p.. in; ..i .UM. him nt 



el tin- K'-'it i" t!"- 111.1:11 ; the membrane. P.C.. ; Ret., 

 .in. 



On Man h j \, 1'ijj. ! he 1 1| i tic vesicle of a thirty-six hour chick 

 emoved as free from adjacent part- as po^-ible .ui<l was 

 placrd in-.tr tin- juncture !' t \\ -f the larg.-~t l>lc.. .! \i-d- on tin.- 

 < li..ri()-,ill.iiitnic TiU'inlir.nii- <>t~ ,t chick of nine and uiu-half days' 

 iiH-iili.itinn. Tl . tlu-n rrturiu-il i<> the incubator \\ '. 



dr\rlo|uiu-nt ] >i< rcd.-d until April fourth \vlu-n the egg \va- 

 I'pi-nrd and tlu- .^rat't. which \va- lar.^r. n-ni' >\-rd. In m\- n< 

 taki-n at the tinir, I notice tin- remark that the ^i.tl't \\.i- hea\il\- 

 |ii-inented. 



1'pon inicro-copical examination of t he >ei tion^, the de-ree of 

 differentiation of th< gl it ]>ro\ed to he (|uite remarkable. In 

 only a few place- i- mito-i-, in the ba-al retinal la\ er c..mnion. . 

 at place- where there are lar^e folds protruding into the po-terior 

 chamber. B\ far the greater jiart of the tiue h ised 



pri'liferatini; and is differentiating. It may be well to rounder 

 this differentiation under four heading-; the chambers, the 

 tapetum and retina, the lenticular region, and the surrounding 

 tissue. 



