Warren Harmon Lewis 411 
ence of buds from the pigment layer. In this specimen, chick 10 days 
and 8 hours old, there were very few wandering cells and the pigment 
Table giving the ages of the chicks gramined, with the absence or presence in the eyes of 
the following structures: (1) Buds from the pigment layer which form wander- 
ing cells, (2) wandering pigmented cells, (3) buds for the sphincter anlage from 
the iris portion of the pigment layer or from its pupillary margin, (4) pigment in 
the pigment layer. 0 indicates none present. The number of (+) indicate in a 
rough way the number or amount present. S indicates eggs incubated during 
the spring and early summer, the others were incubated in the fall. = 
gee. | euicetaree anaes Buds for 
cells. : sphincter anlage. 
Wandering ‘ 
- | pigmented _ Pigment 
: Z | me cells. na ae i 
w | “4 : | : — 
= 3s niger ase Iris. Pupil. 
(= ss | 
+ Soaice 0 | 0 0 0 | 0 0 
+ 98. 0 0 0 0 0 0 
+ 178. 0 0 0 0 0 0 
4 20 8. 0 0 0 0 0 0 
5 =o. 1S 0 0 0 0 0 SP SF 
5 128. 0 0 0 0 0 + 
5 188. 0 0 0 0 0 | o++ 
6 138. + 0 0 0 0 Wiectasata ats 
e oT 0 0 0 0 + | + 
7 =5 ts& 0 0 0 0 + SP SF 
7 38. 0 0 0 0 +f | ar ae 
T = 22 0 se | + ts + See 
8 2 0 Oe ki, “0 0 eco 
oe 10 0 0 0 0 | ~ ++ 
8 128 0 S45 SF Se + | + qn aes 
§ 18 0 0 0 0 | + sp 32 3h 
9 SOnSe - + + + 0 oF a} ar 35 
9 4 0 0 0 0 35 +++ 
9 68 + 0 0 0 ar | SS aeSe ar 
9 19 spar 0 + 0 37 Teor Sr or ar 
10 on (Se Ise Se +e eal + +r SP ae or 
10 1 - + + as | + +++ 
10 8 0 0 - ++ + (++4+4++ 
10 188 ++ - +++ 7 | + |} ++4++ 
10 23 - ~ + - | + | t+4+t 
11 : + 0 + + + 35 35 Fe 
11 Se se 0 + + AF ste staat ahr 
12 22 ~ 0 sh Se + ste 4535 SE SF ar 
14 i + + SP AF + | 3 ab spar ar ae 
in them as well as the general character of the cells indicated their epi- 
thelial origin. In this pecimen a very few buds may have appeared 
from time to time to give origin to these cells and at the moment when 
the 
chick was killed none happened to be attached by connecting pedi- 
cles, these having already broken away. The budding process would 
