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of the air in the intereellular spaces of the roots and rhizomae on 
which the aniraals are living. 
There are two difficulties attached to the carrying out of 
these analyses; firstly, the air quantities in question being so 
diminutive; secondly, the necessity of making the analyses in the 
open air. 
By means of Krogh’s apparatus for microanalyses of gases 1 ) 
the first difficulty is overcome. As well from the cocoon as from 
the intereellular spaces of plants we can get air sufficient for an 
analysis when using this apparatus. 
This apparatus moreover being easily made portable the 
second difficulty also is overcome. 
The above mentioned apparatus was put up in a wooden box, 
the sides of which could be opened completely. The box also 
contained reagents, the necessary basins and the like, and could 
be screwed on to stand or by means of a screwwrench fixed on to 
the thwart of a boat. 
The absolute necessity of making the analysis on the spot 
immediately after having got the plant pulled up is shown by the 
following analyses of air from the intereellular spaces in the 
rhizoma of Carex sp. 
• 
0 lo0 2 
°/o C0 2 
The whole plant 
Analysed 20 
carried home in a botanizing box. 
min. after the taking up. 
13,o 
3,3 
A corresponding analysis from the same plant after 
having been submerged for 8 hours in water. . 
0,4 
8,9 
Thus we see that it will on no account do to bring the roots 
with the corresponding cocoons home to the laboratory submerged 
in water as I tried first; in this way half an hour or more may 
M Aug. Krogh: On the Micro-Analysis of Gases. Skand. Arch. flir 
Physiologie. Bd. 20, 1908. 
