TEMPERATURE AND EMBRYONIC DEVELOPMENT 



139 



The tenrperature tolerance of the Urodele eggs la generally at a lower range than for 

 the Anuran eggs. Further, development at lower temperatures will be retarded for any 

 embryos, within limits of viability. Record the data as follows: 



DATA FOE SPECIES 



STAGE (^0^ of eggs) at HOUBS AFTER FIRST CLEAVAGE* 



DATA FOE SPECIES 



STAGE (50^ of eggs) at HOURS AFTER FIRST CLEAVAGE* 



DATA FOE SPECIES 



STAGE (50^ of eggs) at HOURS AFTER FIBST CLEAVAGE* 



Stage data in the above tables represents the stage achieved by at least 

 50^ of the eggs at each of the temperatures so recorded. 



* Note: The final graph should be corrected by adding the time between insemination and 

 placing the eggs at the various temperatures (2^ hours or more). 



