374 
brought about (fig. 6 d), and this will sometimes disappear by 
the action of the CO,, and reappear with the atmospheric air. 
If aqueous vapour be again allowed to act, the corpuscles 
again assume a rounded form, and, after the experiment has 
been carried on some time, love their colouring matter. ‘They 
do not so readily resume the elongate form after the second 
action of water, and the final stage of the experiment is ob- 
tained when they have become colourless, spherical, and the 
“body”? granulated as well asthe nucleus. The granulation 
of the body, which is not obtained until water has acted two 
or three times and the carbonic acid for a considerable 
period, disappears and reappears at first with alternation of 
the CO, and atmospheric air. The nucleus finally becomes per- 
manent (fig.6e,f). A small pullulation is sometimes obtained 
in the wall of the corpuscle at a late stage of the experiment, 
as drawn in fig. 6 e, f). 
Having witnessed and repeated these experiments in 
Stricker’s laboratory, I was anxious to ascertain whether the 
alternation of any neutral gas with CO, would produce the 
same results as the alternation of atmospheric air. I found 
that by passing a mixed current of CO, and hydrogen the 
granulation was obtained, and that on stopping the CO,, and 
allowing the hydrogen to continue, it disappeared just as 
when atmospheric air was used, the change in the forms of 
the corpuscles also occurring. The same result was obtained 
when using CO in alternation with CO,; and further, by 
simply creating a minus pressure in the gas chamber by 
means of suction, exactly the same effects were obtained as 
when the stream of atmospheric air or inactive gas was used. 
Thus it was sufficiently demonstrated (what, indeed, was 
tolerably certain @ priori) that the disappearance of the 
granulation of the nucleus, on passing the stream of atmo- 
spheric air, is due simply to the diffusion of the carbonic acid 
gas, and not to any specific action of the atmospheric oxygen. 
’ Brucke distinguishes the envelope of the frog’s red corpuscle as “ cecoid ” 
—its contents as “zooid.” Stricker divides Briike’s zooid into a “ body” 
and anucleus. Rollett distinguishes colouring matter and stroma. We 
thus get the tabular statement : 
Stroma. 
Colouring matter. 
Red blood-corpuscle of | (coid = or outer part of stroma. 
ovipara, divisible - Zooid = rest of stroma plus hemoglobin. 
into.j«. - 
Membrane = cecoid. 
Body = zooid minus nucleus. 
(Nucleus = zooid minus body. 
