492 BOTANICAL GAZETTE [DECEMBER 
is K,HPO,. From their experiments they further conclude that peroxidase 
occurs in some plants as enzyme, in others as zymogen, and that the quantity 
present in different plants varies considerably. The smallest quantity in any 
of the plants studied was found in Aspergillus niger and the Saccharomycetes. 
A suggestion is made in this connection which is very important if true. Th 
think it probable that yeasts are capable of producing alcoholic fermentation 
even in the presence of free oxygen because they contain very little or no oxidiz- 
ing enzymes. The experimental evidence for this view is too slender as yet 
to be considered seriously; but if it proves to be true, it will clear up the 
relation of fermentation to the respiratory process. 
The quantitative distribution of peroxidase and the respiratory chromogens 
shows a direct correlation, tissues rich in peroxidase containing much of the 
chromogens, and vice versa. Moreover, the tissues of plants are found to con- 
tain substances which are conceived to “stimulate” the color reactions used 
in detecting peroxidase. The products of alcoholic fermentation, which are 
rich in oxidizable substances, are placed among these stimulators of the forma- 
tion of respiratory pigments. Finally, boiling of aqueous extracts containing 
chromogens is believed to render the formation of pigments impossible, either 
by changing profoundly the chemical nature of the chromogens, or by destroy- 
ing the substances which stimulate the formation of the respiratory pigments 
which are produced by the action of such substances as emulsine and peroxidase 
on the chromogens. Most of the conclusions and suggestions seem to rest on 
a minimum of experimental evidence—Cnar es A. SHULL. 
The flora of Newfoundland.—The report of a botanical expedition to 
Newfoundland by FERNALD includes the mention of many additions to the 
flora of the island, which is now known to possess 783 indigenous species. 
An inquiry into their geographical origin shows that about 60 per cent are boreal, 
including 28 per cent common to southern Labrador and eastern Canada. 
An additional 3.5 per cent are Canadian types not found in Labrador. A 
surprisingly large number of species are southwestern types found also in 
Nova Scotia, New Brunswick, and coastal New England, but unknown or 
rare in Quebec and Ontario. This class contains 274 species, or 35 per cent 
of the Newfoundland flora. At present 16 endemic plants are known, com- 
gus 2 per cent of the flora, 
o explain the abundance of plants identical with those of the Atlantic 
seaboard south of Newfoundland, the writer postulates the former existence 
of a bridge formed by an elevated coastal plain, composed of siliceous soils, 
connecting the island with Cape Breton and forming an ideal highway for 
the northeastward advance of plants which thrive on such soil. This siliceous 
bridge, according to the writer, would have been highly unattractive to such 
34 FERNALD, M. i A bot cone | p qty: 4.5 “wT. ¢ 31. 3 and southern Labra= 
dor. Rhodora 13:109-162. r9r1. 
