134 



J. Thomas Patterson. 



men 



'\^^•y^y^■:■•i•y:'^^■i■^:■:.•.■.■ 





31 



SIC 



Fig. 31. — Median longitudinal section of a blastoderm in a stage of devel- 

 opment coiTes]»onding to that shown in Fig. 30. iii.c.n., marginal cell nucleus; 

 S.C., segmentation cavity. X 65. 



32 



Fig. 32. — A blastoderm showing 346 cells in the surface view, 34 marginal 

 and 312 central (see Table 1, hen No. 9). Note that the marginal cell fur- 

 rows are beginning to cut out into the periblast. X 18. 



