76 BOTANICAL GAZETTE [JANUARY 
were put into a U-tube with the filter paper on which they had been soaked. 
Air was drawn through the apparatus for 30 minutes, after which the carbon 
dioxid was determined at 3-hour intervals for a period of 9 hours in most of 
the experiments. The solvents used in the different experiments were alcohol, 
ether, anilin, chloroform, ethyl acetate, turpentine, benzine, olive oil, acetone, 
benzene, and toluene. 
In each case two parallel experiments were conducted, one with toluene 
vapor drawn through the tube, and one without. In the first experiment in 
which living germs were used they were found rotted at the end of the 9-hour 
period in the tube without toluene. In the other cases it was found that the 
amount of carbon dioxid evolved varied according to the solvent with which 
the germs had been extracted. The order arranged according to the intensity 
of depression is as follows: alcohol, ethyl acetate, ether, benzine, chloroform, 
aniline, turpentine, olive oil, benzene, acetone, toluene. In the tubes with 
toluene this sequence is different, but the toluene vapor in every case caused a 
depression of the amount of carbon dioxid evolved. The authors point out 
that there is a general relation between the quantity of lipoids dissolved by 
acetone, benzene, chloroform, ether, and alcohol, and the depressing effect 
of these substances on respiration. There is, however, no strict proportionality 
between the quantity of lipoids removed and the depression of respiration, as 
would be expected if the depression were due only to the removal of lipoids 
and not to other possible effects of the solvents —H. HAsSELBRING. 
Germination.—GassNER™ has studied the germination characters of seeds 
of two South American grasses, Chloris ciliata and C. distichophylla. The 
behavior of the two species is in the main the same, so we need consider only 
the results with C. ciliata, on which the main work was done. With dry storage 
the seeds show a marked after-ripening. The most favorable period of dry 
storage is 30-40 weeks. With 10 weeks or less of dry storage none will germi- 
nate in darkness at optimum temperature, but after 39 weeks 7-8 per cent 
will germinate under the same conditions. After 9 weeks of dry storage, only 
3 per cent germinate in light, but after 39 weeks 73 per cent respond under 
the same conditions. If the germinators are dark during the early periods 
of germination and then transferred to light, the early subjection to darkness 
greatly reduces the total percentage of germination; the seeds become “dun- 
kelharten.” This effect of darkness appears only when the temperature is 
above the minimum for germination (20°C.). At low temperatures (6- 
10° C.) the germination is not affected by such a period of darkness, GASSNER 
~ nature, which gives great ecological significance to his results. Whatever the 
eclogical value of such work, it must be stated that it adds little to a funda- 
to GASSNER, Gustav, Ueber Keimungsbedingungen einiger siidamerikanischet 
Gramineensamen. Ber. Deutsch. Bot. Gesell. 28:350-364. 1910. 
