1 



Fertilization v/ 



'///. fusion, ^^^, metophose 7//y1Jl''^^?JJ ,y//, , 



Pro nuclear''/' 



1st division 



Interptiase -z 



Centers 

 separated 



Duplication ^, ^ 

 beginning Not separated 



Centers 

 duplicated 



Centers 

 separated 



Duplication 

 beginning 



^2nd division ,,, 

 ' metaphase /y// 



3rd dfvisfon/' 



////////, 



.'^?tqR»)9se^.T5'.°i'.^°'* 



777^ 



/Z Interphase y/ 



Centers 

 duplicated 



Not separated 



Centers 

 separated 



Duplication 

 beginning 



Centers 

 duplicated 



Not separated 



CONTROLS 



A 



7777777777777777. 

 •Control tinnetable: 



2rid division z;/;^ 

 completed >;^ 



Pronuclear vx/lst division ' 



..MERCAPTpETHANOL 



dupiiJafId Separated Further 



Not separated ^^ duplicotion separation 



'VfV 



Recovery. 



Formation of 

 4 polar spindle 



^CbntroV;%>^ 



4- way 

 division 



Duplication 

 of half centers 



Monopolar 

 metaphase 



4 th' division "^ 

 Oy completed 



Separated 



Duplication 



beginning 



FOUR -WAY DIVISION 



FOLLOWING BLOCKAGE 



WITH MERCAPTOETHANOL 



Normal 4-*-8 division 



B 



