158 ETHEL BROWNE HARVEY. 



PLATE II. 



FIG. 16. Same 20 min. later. 



FIG. 17. Same 10 min. later. 



FIG. 18. Same 15 min. later. 



FIG. 19. Egg of Echinus subjected to H at metaphase for i hr. then air for 

 15 min. 



FIG. 20. Same 20 min. later. 



FIG. 21. Same 20 min. later. 



FIG. 22. Same 20 min. later. 



FIG. 23. Same 20 min. later. 



FIG. 24. Egg of Strongylocentrolus subjected to H at metaphase for 15 min., 

 then air admitted for 30 min. 



FIG. 25. Same egg 20 min. later. 



FIG. 26. Same 20 min. later. 



FIG. 27. Same 2\ hrs. later. 



FIG. 28. Same 15 min. later. 



FIG. 29. Same 15 min. later. 



