CHAPTER VIII 

 THE ACTIVATION OF UNFERTILIZED EGGS 



We have seen that the fundamental control of the cleavage 

 mitoses is alike in rabbit and sea-urchin ova. We shall now 

 inquire whether the activation of mammalian eggs is also 

 similar to that of other forms. 



With the exception of the three 2-cell rat eggs described 

 by Mann (1924) there are no observations of a possible 

 normal parthenogenetic development of unfertilized tubal 

 eggs in vivo. With the exception of a single observation by 

 Champy (1927), the first investigation of the behavior of 

 unfertilized tubal ova placed in tissue culture is that of 

 Pincus (1930). His data are presented in Table XVII. 



TABLE XVII 



(C = Chicken. 



R = Rabbit. 



P = Plasma. 



E = Embryo Extract.) 



