SECT. 4] HEAT-PRODUCTION OF THE EMBRYO 703 



& Hasselbalch, those of Hasselbalch, those calculated from Bohr & 

 Hasselbalch's data, those of Lussana, and those of Murray, whose 

 papers will be mentioned below. As Fig. 144 shows, there are a 

 certain number of points above 0-75, although the greater number 

 lie just below that figure. What is probably significant is that the 

 latter occur mostly after the 8th day of development, while the 



G> 



100- 



09- 



8- 



07 



© R.Q. calculated from 

 chemical analyses 

 © Experimentally determined 

 by Bohr and Hasselbalch 

 and given by them 

 Q ditto, but calcd. from their 

 figures by Needham 



O Experimentally determined 



by Lussana 



O Corrections for alkali 



reserve 



06 



I 



5 10 



Days 

 Fig. 144. 

 former all occur before it. No high point is to be found after the 

 loth day^. Lussana's points agree well with those of Bohr & Hassel- 

 balch and Hasselbalch. Of the high respiratory quotients, the only 

 point actually given by Bohr & Hasselbalch was 0-890 for the 4th 

 day; the others were all calculated from their data in 1927 by me. 

 At the same time I also attempted to see to what extent the alkali 



1 Dickens & Simer give the R.Q. of 5th day chick embryos in vitro (phosphate- 

 Ringer, pH 7-4, 38°, with 0-2 % glucose) as unity. 



