b2 65 



Fig. VIII. 



Development of Egg-fragments after horizontal or oblique ScctionA 



52, 53, Twins, after oblique or horizontal section near upper pole ; 54, trefoil, 

 lower half, horizontal section above equator; 55, 56, twins, after oblique section, 

 larger lower, smaller upper fragment; 57, 58, 59, twins, after slightly unequal 

 oblique section; 57, trefoil from lower fragment, 58, upper fragmertt (failed to 

 segment), 59, trochophore of 24 hours developed from 57; 60, 61, 62, twins, 

 horizontal section below equator ; 60, trefoil, lower fragment, 61, 2-cell stage 

 of same, 62, upper fragment, 2-cell stage; 63, trefoil, lower fragment, horizontal 

 section , polar lobe too small ; 63a, trefoil lower fragment, with polar lobe 

 slightly too large ; 64, 65, twins, plane uncertain, 64 undeveloped fragment, 65 

 trochophore, 24 hours. 



1 In these and the following figures the plane of section is indicated by the 

 small accompanying diagram, the fragment studied being marked with a bL.ck 

 dot. 



