770 



THE RESPIRATION AND 



[PT. Ill 



chick embryos were all taken during a very short period, namely the 

 2nd to the 5th day of incubation, and it is possible that a more com- 

 plete study would reveal a greater fall. In Table 9 1 it will be noted 

 that, following the usual course, U. is always negative, and, though the 

 N.G.R. is fairly high, the O.G.R. is low. The R.R. shows some indica- 

 tions of a fall with age, agreeing with other figures for metabolic rate. 



0,3 0,S 0,3 -7,2 t5 1,8 <?,7 2,'t 2,7 Jfi 3,3 3,6 3,3 %Z %5 .¥,8 5,i 5/J- 5,7 6,0 



Trockengewic/rf-efnes Embryos ff77grj 



Fig. 175- 

 O in Ringer solution : < in avian serum 



It appears that in general the N.G.R. declines with age^. This 

 has been found to be true in several investigations : 



Rat liver 



Rat kidney 



Rat embryo (whole) 



Rat chorion 



Human placenta 



Chick liver 



Chick heart {in vitro) 



Chick embryo (whole) 



Rat lens and placenta 



Rat placenta 



Rosenthal & Lasnitzki 



Rosenthal & Lasnitzki 



Negelein 



Negelein 



Loeser 



Tamiya 



Warburg & Kubowitz 



Kumanomido 



Fujita 



Adler 



The converse, i.e. that the N.G.R. rises with age, has only been 

 observed in one case : 



Chick retina ... ... Tamiya 



The aerobic glycolysis rate, on the contrary, may either rise or fall 

 with age; 



Rosenthal & Lasnitzki 



Loeser 



Kumanomido 



Rise: Rat liver 



Fall: Human placenta 



Chick embryo (whole) 



^ Fertilisation, according to Ashbel, augments the N.G.R. of echinoderm 



eggs. 



