[Vor. 5 
252 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
acid for 12-15 hours underwent a marked acceleration of the 
ripening process. Waller (710) concluded after a quantitative 
colorimetric study of the Mirande-Guignard hydrocyanie acid 
phenomenon that the evolution of the acid, in relation to elec- 
trieal response as an index of life, was a post-mortem re- 
sult. This, in view of the rapidity with which acid produc- 
tion has been noted, argues for an extremely rapid action of 
the anaesthetic on permeability. In later papers Vinson 
(710, 2108) showed that the fore-mentioned forced ripening of 
dates could be effected by a great variety of substances, 
volatile and liquid. In general, the more volatile the sub- 
stance the quieker the action. It appeared from the results 
that the chemical structure of the stimulants was not a factor, 
but that the stimulus was due to the killing of the protoplasm 
by penetration of the stimulant, with consequent release of 
previously insoluble intracellular enzymes. This explanation 
was supported by heating dates to varying degrees. A tem- 
perature that killed the cellular protoplasm without injuring 
the enzymes effected ripening. That ripening depended upon 
the enzyme relation or condition appeared evident from the 
faet that, despite the presence of considerable invertase, the 
sucrose of green dates was very slowly inverted; if, however, 
the fruit cells were crushed by grinding, rapid inversion re- 
sulted. It is believed that by the death of the protoplasm by 
toxie, thermal, or mechanical means, ripening is facilitated by 
the conversion into soluble form of an enzyme previously held 
in insoluble condition by the living protoplasm. 
Heckel (’09) reported the action of anaesthetics in rapidly 
liberating cumarin from leaves of Liatris spicata, Angraecum, 
and other plants, and melilotol from Melilotus officinalis, the 
phenomena being accompanied by plasmolytie changes. In 
a later communication ('10) he announced that chloroform 
and ether both accelerated vanillin formation in Vanilla plani- 
folia by eausing exeretion of water and hastening the drying 
process. 
Results of a most striking nature with special bearing on 
the writer's problem have been announced by Willaman (717 5h 
who studied the effect of anaesthetics upon the суапогепеНс 
