54 BOTANICAL GAZETTE [JULY 
perature rather high, the roots probably absorbed a certain quantity of 
water which was unable to escape in proportionate amounts, because of 
the absence of transpiring leaves. In this way a large amount of water 
might have accumulated in the root system and trunk. Of the roots, 
those growing in the water have the thinnest walls, both in the epi- 
dermis and cortex, and when the tension became too great, elongation 
of the subepidermal cells took place. All roots in the water had 
cushions more or less developed, while the soil roots failed to show 
them. No indications of any cedematous structures were to be found 
in the branches.— HERMANN VON SCHRENK, Shaw School of Botany, St. 
Louts. 
ON THE PRESENCE AND LOCALIZATION IN CERTAIN 
POMACEOUS SEEDS OF THE PRINCIPLES PRODUC- 
ING CYANHYDRIC ACID. 
Ir is well known that certain of the Amygdalacez contain two 
principles which in their reaction upon each other in the presence of 
water produce cyanhydric acid. These two principles are emuésin, a 
ferment, and amygdalin, a glucoside. The amygdalin and emulsin 
occur in different cells in the plants which contain them, so that lacer- 
ation of tissues is necessary for production of cyanhydric acid. It is 
not the Amygdalacez alone that contain the principles that generate 
cyanhydric acid, but they are to be found in many plants of different 
families. 
Kobert,* who gives a very complete enumeration of such plants. 
mentions the seeds of Malus communis as containing emulsin and 
amygdalin. He does not insist upon the presence of these substances 
in apple seeds, and does not mention any other of the Pomacee. It 
seemed well, therefore, to extend the investigation throughout the 
group. To determine the presence of the generative principles of 
cyanhydric acid in pomaceous seeds I followed the classical experi- 
ments for the determination of this acid, and the methods employed 
by M. L. Guignard in his earlier investigations of this subject. 
1. The seeds are crushed in a glass mortar in a small amount of 
water, and tested as to a development of the odor of bitter almonds. 
2. The product is diluted in a larger amount of water and distilled 
in a glass retort. The first portions of the liquid passing over in dis- 
* Lehrbuch der Intoxicationen §10. 
