1914] ATWOOD—GERMINATION OF AVENA 403. 
showed much lower rates the same period than were obtained 
in air. 
Oxygen absorption tests of freshly harvested wild oats were 
made during July 1913 at temperatures of 1692 C. and 26°2'C. 
It was thought possible that the failure or success of the VAN’T 
Horr temperature law of chemical reaction to hold with the fresh 
seed might, in connection with the other data, throw some light 
on the power of the seed coat to exclude oxygen. Summarizing 
a number of readings, it was found that Bee 
the rate at 26°2 C. 0.160 
the rate at 16°2 C. 0.067 
=2.38. 
This is quite what might be expected if the coat offered no re- 
striction to gaseous penetration, and appears at first to conflict 
with the data derived on this point in other tests. However, we 
cannot as yet say what effect such a temperature change may exert 
on the permeability of the coat, which is a non-living structure. 
It is a well known fact that the solubility of oxygen in water 
decreases with a rise in temperature. Thus, the absorption at 
35° C. is 56.9 per cent of that occurring at 5° C. GASSNER in a 
recent article (28), as reviewed by LEHMANN (48), believes that 
€ beneficial results obtained in germination of Chloris ciliata 
through the use of low temperatures may be due to the greater 
absorption of oxygen at these cemeratures. He employed tem- 
peratures varying from 5° C. to 34° C. LepPESCHKIN (50) and 
others, however, have pointed out the fact that the permeability 
of living protoplasm to gases increases with rising temperature. 
It is thus quite possible that the problem of oxygen absorption by 
the grasses may be complicated by the opposite influence of high 
temperature on the solubility of oxygen in the water in the seed, 
and on the permeability of the seed coat itself. Conclusions on 
these tests must hence be delayed pending further investigation 
of the effect of varying temperatures on the permeability of non- 
living membranes to gases. 
As it was noted that in every germination test a large number of 
seeds laid dormant, yet if forced by searing would promptly or 
minate, the experiment was tried of testing the oxygen-absorption 
