STUDIES WITH THE CENTRIFUGE 



TABLE 2 



39 



STAGE AND DURATION OF EXPOSURE IN THE CENTRIFUGE 



16-CELL STAGE 



Normal Dead 



PER CENT 

 MORTALITY 



Normal control— fertilized immediately after removal 



from the animal 203 



Centrifuged for | minute — then fertilized 62 



Centrifuged for 1 minute — then fertilized 58 



Centrifuged for 1^ minutes — then fertilized 143 



Centrifuged for 2 minutes — then fertilized 80 



Centrifuged for 2^ minutes — then fertilized 1 144 



Centrifviged for 3 minutes — then fertilized j 153 



TABLE 3 



Tables 1 and 2 combined 



TABLE 4 



GASTRULA STAGE 



STAGE AND DURATION OF EXPOSURE IN THE CENTRIFUGE 



Normal 



Dead 



PER CENT 

 MORTALITY 



Normal control 1038 



Centrifuged for 2 minutes — then fertilized 



Centrifuged for 2 minutes — 40 minutes after fertiliza- 

 tion 



Centrifuged for 2 minutes — 50 minutes after fertiliza- 

 tion 



572 



398 



175 



931 

 322 



348 



213 



47 

 36 



46 



55 



