286 LEAVES 



roots, stems, and leaves of plants, and often in fruits and seeds. 

 They are complex substances. Amygdalin (C20H37NO11), es- 

 pecially abundant in the pits of the Bitter Almond, Peach, 

 Apricot, and other members of the plum family, yields glucose 

 (C6H12O6), hydrocyanic acid (HCN), and benzaldehyde (CeHg 

 CHO) when decomposed. Coniferin (C16H22O8), a glucoside 

 common in coniferons trees and Asparagus, yields glucose and 

 coniferyl alcohol (C10H12O.). There are numerous glucosides in 

 plants and they yield ■various kinds of substances when decom- 

 posed and sometimes other sugars instead of glucose. 



Hydrocyanic acid is very poisonous to animals and glucosides 

 containing it sometimes kill animals. The saponins, present in 

 Corn Cockle and Cow Cockle, are poisonous and make the seeds 

 of these plants objectionable impurities of the small grains, and 

 the same is true of sinigrin, a poisonous glucoside in seeds of 

 some of the Mustards. Some Beans, as the Burma Bean, contain 

 phaseolunatin, a poiso nous glucoside. Since glucosides commonly 

 yield sugar when br oken down by their respective enzymes, they 

 are regarded as storage forms of food. 



Alkaloids. — The alkaloids are the most poisonous of plant 

 substances and probably function chiefly in protecting plants 

 against animals, as they are commonly unpleasant to the taste 

 besides being poisonous. They occur in all parts of plants. 



Both man and livestock are often k illed by eating plants con- 

 taining alkaloids. An extremely poisonous one, called muscarine, 

 is present in some Toadstools. When these Toadstools are mis- 

 taken for Mushrooms and eaten, death usually results. The 

 poison hemlock {Conium maculatum), found in pastures and waste 

 places, contains coniin, and hvestock and sometimes people are 

 killed by eating the roots, stems, or leaves of the Hemlock. In 

 the Nightshade family, the family to which Tomatoes and the 

 Irish Potato belong, there are a number of plants containing 

 alkaloids, such as atropine and solanin, that cause injury and 

 sometimes death in animals. People are sometimes killed by 

 eating their berries. Ptomaines, the alkaloids produced in decay- 

 ing meats by Bacteria, are a source of much trouble. A number 

 of alkaloids, such as nicotine in Tobacco, morphine in the Poppy, 

 quinine from the bark of the Cinchona tree, strychnine from the 

 seeds of Nux Vomica, caffein and thein in Tea and Coffee, etc., 

 are used intentionally by people for their various effects upon the 



