SECT. 4] HEAT-PRODUCTION OF THE EMBRYO 



679 



this curve is not an increment curve, but shows the total amounts 

 consumed up to each time point, in cubic milHmetres of oxygen. 



Z/eg/ers ModeJ//l/S 12 MP 15 ^ fJS 17 



Hours 

 Fig. 130. {Continuous line =^ in air; dotted line = in oxygen.) 



The second figure shows the same thing for the eggs oi Rana temporaria 

 for the first 70 hours after fertiHsation, and in the third figure is 

 shown an increment curve, i.e. the amounts of oxygen consumed 

 per hour by 1000 eggs. As is evident, the rise in respiratory rate 



