Expelling C0 2 from the Blood. 



207 



as to the influence of variations in oxygen tension upon C0 2 

 capacity. 



Our experience has led us to believe that the quality of exhi- 

 biting this reaction depends upon the previous treatment of the 

 blood. Thus in our hands freshly drawn dog's blood shows it 

 when defibrinated, but not when oxalated. The following is 

 typical of our results. 



Equilibrating Gas Mixture Defibrinated Blood Oxalated Blood 



Air plus 5-6% CO2. . .53.5 volumes per cent. CO2. . .55.0 volumes per cent. CO2 

 Nitrogen plus 5-6% " 58.5 " " " 55-0 



Experiments are under way to determine whether the influence 

 of C0 2 upon oxygen capacity is likewise lacking in oxalated normal 

 blood. 



Variations within the body in respect to the capacity of the 

 blood for interaction of the two gases would afford a possible ground 

 for reconciling some otherwise difficult discrepancies. 



112 (1572) 



Observations on the connective tissue ground substance in living 

 amphibian embryos. 



By George A. Baitsell. 



[From the Osborn Zoological Laboratory of Yale University.] 



Results obtained from a study of the development of con- 

 nective tissue in amphibian embryos, as presented in a previous 

 communication, 1 show that the process is essentially in agreement 

 with the intercellular theory of connective tissue formation. 



The previous observations were made on preserved amphibian 

 material. It has been found possible this spring to demonstrate 

 the presence of a primary ground substance in various stages of 

 living amphibian embryos. Living embryos, ranging from a late 

 gastrula stage up to the free-swimming embryo, have been dis- 

 sected under the binocular microscope and it has been possible in 

 all stages to show, as was previously demonstrated in the prepared 



1 A report of this work was presented at a meeting of the National Academy of 

 Sciences held at New Haven, November, 1919, and an abstract appears in the 

 Proceedings of that Society, 1920, VI, 77. 



