CONVOLVULACEÆ. =Bindweeds= (_Convolvulus sepium_ L. and _C. arvensis_ L.). The creeping rootstocks and foliage, as well as the seeds, are held to be more or less poisonous if eaten in quantity, and as long ago as 1872 Olver recorded (_Veterinarian_, 1872) that pigs which ate freely of _Convolvulus_ died. These species, when eaten in considerable quantity, appear to be cathartic and purgative, causing symptoms resembling those due to jalap. REFERENCES. 82, 141, 190, 203, 254. SOLANACEÆ. =Thorn Apple= (_Datura Stramonium_ L.). This species is an escape from cultivation, but on occasion occurs plentifully in gardens, and if allowed to seed may escape to arable fields and find its way to stock, though it does not appear to have done so in Britain. Several species of _Datura_ are recognized as virulent poisons in North America, where they are known as Jimson Weeds. All parts are poisonous, especially the seeds, which have a somewhat sweetish taste, and have frequently caused accidents to children who have eaten them. Cases are recorded in the United States in which cattle have been poisoned by eating the leaves of young plants in hay. Live stock, however, usually avoid the plant, which has an unpleasant odour and taste, while the seeds are enclosed in thorny capsules. Walsh states that the seeds are very fatal to young ostriches. Drying does not destroy the toxicity. _Toxic Principle._ The Thorn Apple is usually stated to contain the highly poisonous narcotic alkaloid _Daturine_, but this appears to be a mixture of the two alkaloids _Hyoscyamine_ (C_{17}H_{23}O_{3}N) and _Atropine_ (C_{17}H_{23}O_{3}N), which, together with the alkaloid _Scopolamine_, or _Hyoscine_ (C_{17}H_{21}O_{4}N), have been found in the plant, the principal constituent being Hyoscyamine. In some analyses as much as 0·33 per cent. of Atropine has been found in the seeds, and 0·2 per cent. in the leaves (Pammel). The three alkaloids occur together to the extent of 0·48 to 3·33 per cent. in the leaves, 0·43 per cent. in the flowers, and 0·1 per cent. in the root, Hyoscyamine predominating (Esser). An investigation conducted at the Imperial Institute (_Bul. Imp. Inst._, 1911) showed the amount of alkaloids in European specimens to be:— Seeds 0·21 to 0·48 per cent. Leaves up to 0·4 „ Stems average 0·22 „ Roots average 0·17 „