422 Dr. C. Shearer. Heat Production and Oxidation 



At end of experiment 100 per cent, of eggs showed fertilisation membranes 

 and commencing two-cell stage. Kjeldakl determination gave 9 mgrm. egg 

 nitrogen present. 



At this rate 146 - 2 mgrm. egg nitrogen would consume 1380 c.mm. oxygen 

 in the first hour following fertilisation, 1380 c.mm. oxygen being equivalent 

 to T97 mgrm. 



The heat produced by 280 mgrm. egg nitrogen in the first hour following 

 fertilisation,, as shown in the early part of this experiment, was 6 - 35 grm.- 

 calories. So that 



Q = j|f = 3-22. 



The heat production rose in the fifth bour to 28 grm.-calories, and to 

 74 - 4 grm.-calories in the 11 hours in this experiment. The corresponding 

 C0 2 determination for this experiment gave a respiratory quotient of - 95. 



Experiment 3. 



800 c.c. of ripe well washed E. miliaris eggs were placed in Flask No. 3, 

 763 c.c. plain sea-water being placed in Flask No. 4, acting as a control 

 under the conditions of the experiment with flasks sunk in the water of the 

 thermostat and air-bubbled through both flasks, h for flask No. 3 was - 0238 

 while that for Flask No. 4 was 0"0236. Temperature was adjusted 

 all round to within a hundredth of a degree to 14'5° C. No sperm were 

 added. Galvanometer readings were commenced. At the end of 1 hour 

 Flask No. 3 had given off 3'6 grm.-calories of heat. A Kjeldahl determina- 

 tion on the flask contents gave 431 mgrm. egg nitrogen present. In the 

 same time 8 mgrm. egg nitrogen of the same batch of egg material, consumed 

 15*1 c.mm. oxygen. Therefore 431 mgrm. of egg nitrogen would consume at 

 this rate 812 c.mm. oxygen in this time, as 812 c.mm. oxygen equal 

 117 mgrm. O2 we get value of 



Q = H7 = 307 



for the unfertilised egg. The value obtained for the fertilised egg of 

 E. miliaris in the two previous experiments was 3-215 and 3 - 22 respectively. 

 Thus the value of Q is somewhat different in the two cases. 



It is doubtful, however, if much significance can be attached to this 

 difference. The gonads of so many females have to be used for making 

 determination on the heat production of the unfertilised egg, that it is 

 impossible that they should all be in the same stage of ripeness. Some of the 

 gonads are certain to be slightly over ripe, and their eggs will probably 

 cytolyse on being placed in the vacuum flask, and will give off an abnormally 



