BIGELOW: EARLY DEVELOPMENT OF LEPAS. Ai) 3) 
TABLE OF THE CELL-LINEAGE OF LEPAS. 
2 cells. 4 cells. 8 cells. 16 cells. 32 cells. 62 cells. 
a‘? (ec’bl.) aS-4 (ec’bl.) 
en a™6 (ec’bl.) 
atl a63 i 
os a™5 (ms’bl.’) 
a®1 (ec’bl.) 
b78 (ec’bl.) 
b4-2 (ec’bl.) 6 
bt-7 (ms’bl.’) 
p52 
b7°6 (ec’bl.) 
bel 16-3 sat 
b7-5 (ms’bl.’) 
Fertilized b5-1 (ec’bl.) 
Ovum 
c#2 (ec’bl.) c&-4 (ec’bl.) 
_— | c@6 (ec’bl. 
ctl 6:3 ew ( ) 
c™5 (ms’bl.’) 
cd? cl (ec’bl.) 
(y*) 
d*2 (ec’bl.) 
(3) 
d-2 (ms’bl.) 
d*1 (en’bl.) 
(y’) 
y?, y°, y*, y® designate the yolk-bearing macromere; (1), (2), (8), the three 
micromeres containing ectoblast ; ec’bl., ectoblast ; en’b/., entoblast; ms’dl., primary 
mesoblast , ms’bl/.’, “secondary mesoblast.” 
