508 BOTANICAL GAZETTE | DECEMBER 
Helobie. 
Butomus ie 
Carpad. Lzviiflore. 
Scitaminee. 
Ee Glumifiore, (Grasses.) 
Principes. 
Synanthe. 
Spatiflore. 
Farinose. 
Glumiflore. (Sedges.) 
; Pandanales. 
Petalad. Li#iifore. 
Microsperme. 
or 
ALTHOUGH THE EXISTENCE of acid secretions by roots has been known 
for nearly forty years, no exatt knowledge of the chemical composition of 
these secretions was at hand. To fill this gap, and to reinvestigate the 
opinion of Molisch that diastatic and inverting enzymes are secreted by the 
root, Czapek undertook the investigations to which brief reference has already 
been made on p. 65 of this volume. In the full paper” the excretions of 
roots are exhaustively discussed. A translation of the author’s own summary 
is here given, 
The roots of the higher plants, under culture either in a saturated atmos- 
phere or in water, secrete a series of dissolved substances, partly inorganic, 
partly organic. 
The droplets which are generally seen on root hairs in a saturated atmos- 
phere are produced by filtration under pressure, and appear only when the 
hair cells are highly turgescent. 
Of inorganic substances which roots give off in water may be named: 
potassium, calcium, magnesium, hydrochloric acid, sulfuric acid and phos- 
pPhoric acid. Only potassium and phosphoric acid are present in any con- 
siderable quantity ; they are found in the form of primary potassium phos- 
phate, in many cases by far the predominant constituent of the residuum 
upon evaporating the root excretions. 
€ mono-potassium phosphate (KH,PO,) arises in all probability in 
great part from living cells of root hairs, the epidermis, and the outer cortex 
in the piliferous region. . 
Neither acetic acid nor lactic acid, as was asserted on many sides, is found 
in the root excretions. Formic acid, in the form of its potassium salt, is of not 
*” Jahrbiicher f. wiss. Botanik 29 : 321-390. 1896, 
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