380 MR. A. J. EWART ON ASSIMILATORY INHIBITION. 
of nearly 5° C. was needed to produce the same results as 
previously. 
For purposes of comparison a few of Jumelle’s results with dry 
heat are here given :— | 
At 40? C.— Evernia Prunastri. After 1 day still assimilated ; 
after2 days gave off more CO, than it absorbed ; 
after 3 days respired only. 
» »  Gleocapsa and Palmoglea. After1day assimilation 
is but little greater than respiration; after 
2 days all power of assimilation is lost. 
At 45? C.— Dicranum scoparium after 1 day gives off CO, and 
absorbs O in sunlight. 
." 5 Glæocapsa and Trentepohlia after 1 day respire 
only. 
At 50° C.—Evernia Prunastri. After 1 hour still assimilates ; 
after 3 hours respiration is stronger than assimi- 
lation ; after 14 hours respires only. 
» » Cladonia rangiferina. After 5 hours assimilation 
is still stronger than respiration, after 14 hours 
gives off CO, in sunlight. 
At 55? C.—After 1 hour Lichens give off CO, in sunlight ; 
but after 7 days Cladonia rangiferina still re- 
spires, though with but 1 to jl its pristine 
vigour. 
» » ` Orthotrichum affine after 7 days showed almost 
norma] assimilation. 
At 60° C.— Evernia Prunastri after 9 hours still respired. 
On comparing these results with those given in the four 
preceding tables, it will at once be seen that the temperatures 
mentioned by Jumelle as necessary to produce the results given 
are, except with Orthotrichum and Gleocapsa, where the results 
obtained coincide fairly well, much too low. This diserepancy 
does not indicate any lack of accuracy in Jumelle's observations, 
but simply emphasizes the fact that the gas-analytical method is 
not so delicate and discriminatory as the Bacterium method is. 
Thus in Dicranum a power of assimilation is still present long 
after it should, according to Jumelle, have ceased. In the leaves 
of the apical tuft of this plant, owing to the relative difficulty 
with which gases will diffuse to and fro from the inner and more 
protected leaves, and to the shading from the light of the inner 
