` 1918] 
BONNS—ETHERIZATION AND ENZYME ACTIVITY 233 
integrity of the seed-coat. Seeds with uninjured coats re- 
mained viable after subjection to anaesthetie vapors or solu- 
tions for almost a year; those with perforated coats were 
killed. Burgerstein (206) also opposed Schmid’s view by 
reporting that 24 hours’ exposure of seeds of Phaseolus, 
Cucurbita, Helianthus, Zea, etc., to ether vapor resulted in 
germination stimulus, while seeds with previously imbibed 
water merely suffered a retardation. Chloroform in the same 
respective dosage was found to be more toxic. The germina- 
tion of barley was stimulated, according to Kiessling (711), 
by subjection to ether vapor for 80 minutes; a longer treat- 
ment resulted in a reduction in rapidity and per cent of 
germination. Hempel (’11), on the contrary, found that ether 
retarded the germination of Pisum seedlings. 
EFFECT ON PERIODICITY 
Under this heading may be grouped the investigations deal- 
ing with the forcing effect of anaestheties on growth activity, 
as distinet from effects on germination as a phase of growth. 
Such forcing action of ether vapor in breaking or suspending 
the period of inactivity in the annual cycles of many plants 
has been the subject of considerable experimentation since 
Johannsen (706) first called attention to the subject. А large 
part of the literature on the subject deals with methods 
and results as applied in the floricultural and horticultural 
field, and no review of the publications bearing on this phase 
is here attempted. Mention may be made of the work of 
Aymard ('04), Howard (206, 710, 75, ?15?, 715», 715^), —who 
has devoted a eonsiderable amount of time to experimental 
work along this line with twigs, potted plants, bulbs, her- 
baceous perennials, and seeds,—and the experiments of Stuart 
(710). 
Behrens (’06) regarded the shortening of the rest period 
of seeds by ether vapor as a pure stimulus effect independent 
of seed-coat permeability. Burgerstein (’06) noted a forc- 
ing aetion on bulbs of Narcissus with the same ether dosage 
that caused inhibition in Alliwm Cepa. Tulips, he reported 
to be unaffected by the anaesthetic. Jesenko ('11) varied the 
