THE ACTIVATION OF UNFERTILIZED EGGS 109 



TABLE XIX 



The Effect of Various Treatments upon the Activation of Rabbit 

 Ova IX Vitro. (From the Journal of Experimental Zoology) 



Date 



18/1/34 



24/1/34 



24/1/34 



24/1/34 



20/IX/35 



20/IX/35 



21/IX/35 

 21/IX/35 



21/IX/35 



20/IX/35 

 20/IX/35 

 21/IX/35 

 21/IX/35 



18/IX/35 



Treatment 



3 minutes in 2.8 c.c. H/10 butyric 

 acid + 50 c.c. Ringer-Locke fol- 

 lowed by 3 mins. in 8 c.c. 2.5% 

 NaCl -f 50 c.c. Ringer-Locke 

 followed by plasma culture 



3 minutes in 5 c.c. N/10 butyric 

 acid -f 100 c.c. Ringer-Locke 

 followed by hypertonic solution 

 as above 



3 minutes in 7.5 c.c. N/10 butyric 

 acid -|- 100 c.c. Ringer-Locke 

 followed by hypertonic solution 

 as above 



3 minutes in 10 c.c. N/10 butyric 

 acid -]- 100 c.c. Ringer-Locke 

 followed by hypertonic solution 

 as above 



10 minutes in 1.8% Ringer-Locke 



5 minutes in 1.8% Ringer-Locke 



8 minutes in 1.8% Ringer-Locke 

 8 minutes in 1.6% Ringer-Locke 



8 minutes in 2.0% Ringer-Locke 



2 minutes exposure to 45.5° C. 



3 minutes exposure to 45.5° C. 

 2^ minutes exposure to 45.5° C. 

 3 minutes exposure to 45.5° C. 



2 minutes exposure to 60° C. 



Result 



Cumulus partly dispersed ; one 

 ovum with 2 polar bodies; 

 7 with 1 polar body; much 

 shrinkage 



Cumulus partly dispersed; 2 

 ova with 2 polar bodies; 

 with 1 polar body; much 

 shrinkage 



Plasmolysis of ova 



Plasmolysis of ova 



Cumulus intact; only 1st polar 



body 

 Cumulus intact; only 1st polar 



body 

 3 polar bodies in 5 hours 



1 egg with 2 polar bodies; 

 1 egg with 3 polar bodies 



2 polar bodies in 3 hours 

 3^ with 2 polar bodies 



2 or 3 polar bodies per egg 

 2 polar bodies formed 

 2 or 3 polar bodies per egg 

 No polar body formation 



ducing activation, and that more drastic treatment (e.g., 

 longer treatment, or Loeb's treatment) is only occasionally 

 effective. This indicates that the optimum conditions for 

 the activation of rabbit ova are different from those em- 

 ployed with sea-urchin eggs. - The data on the experiments 

 with ova heated to 45° to 47° show that this heat treatment 

 is most effectively activating. 



We may conclude therefore that certain of the methods 

 ordinarily employed in the artificial activation of non- 

 mammalian ova are also effective in activating mammalian 

 eggs. In a preliminary group of experiments (unpublished 



