FISH AND ARROW POISONS 55 



Nekoeid will poison fish in proportion of 1-10,000,000. The poison will take ef- 

 fect in one hour. The water poisoned with the substance will cause the fish to 

 make an effort to get away from the poison, they are in a horizontal position, 

 breathe heavily, come to the surface of the water and try to jump out and finally 

 breathing becomes increasingly difficult and at last they turn on their backs and 

 die. 



Under poisoning from cherry, sorghum and a few other 

 Hydrocyanic plants, an account has been given of poisoning from hydro- 

 Poisoning, cyanic acid. It may be convenient to bring together some of 

 the plants from which the very poisonous substance, prussic 

 acid, has been obtained. 



Maurits Greshoff of the Colonial Museum in Holland has taken the pains 

 in a paper on Cyanogenesis to give the distribution of Prussic acid in the vege- 

 table kingdom, the Hydrocyanic acid being found in a great many different 

 plants. The following list gives the orders in which this substance occurs. 



Ranunculaceae (Aquilegia vulgaris, Thalictrum aquilegifolium} . Berberi- 

 daceae (Nandma domestica). Cruciferae (Lepidium sativum), Bixaceae (Gyno- 

 cardia odorata, Hydnocarpus venenata, Kiggelaria africana, Pangium edule, 

 Ryparosa caesia, Taraktogenos Blumei, Trichadenia zeylanica} ; Sterculiaceae 

 (Sterculia) ; Tiliaceae (E chin o car PUS} ; Linaceae (Linum usitatissimum) ; 

 Rutaceae (Citrus medica) ; Dichopetalaceae (Chailletia cymosa) ; Olacaceae 

 (Ximenia americana} ; Celastraceae (Kurrimia zeylanica) ; Rhamnaceae (Rham- 

 nus Frangula) ; Sapindaceae (Cupania, Schlelchera trijuga) ; Anacardiaceae 

 (Corynocarpus laevigata} ; Leguminosae-Papilionaceae (Lotus arabiscus, In- 

 digofera galegoides, Phaseolus lunatus, Vicia saliva, Dolichos Lablab} ; 

 Rosaceae (Amelanchicr vulgaris, Chamaemeles, Cotoneaster integerrima, Cratae- 

 gus Oxyacantha, Eriobotyra japonica, Nuttallia cerasiformis, Ostcomeles, Pho- 

 tima, Pyrus, Prunus Atnygdalus, Pygeum africanum, Spiraea Aruncus) ; Saxi- 

 fragaceae (Ribes aurcum) : Combretaceae (?Combretum constrictum} ; Myrt- 

 aceae (tPsidium montanum} ; Melastomaceae (Memecylon) ; Samydaceae 

 (Homalium) ; Passifloraceae (Passiflora quadrangularis, Tacsonia) ; Caprifoli- 

 aceae (Satnbucus nigra) ; Rubiaceae (Plectronia dicocca) ; Compositae (Char- 

 dinia xeranthemoides, Xcranthemum annuum) ; Sapotaceae (Isonandra, Lucuma 

 bonplandia, Payena latifolia) ; Asclepiadaceae (Gymnema latifolium} ; Convol- 

 culaceae (Ipomoea dissecta) ; Bignoniaceae (Osmohydrophora nocturna) \ 

 Euphorbiaceae (Bridelia ovata, Elateriospennum Tapos, Hevea brasiliensis, Ja~ 

 tropha augustidens, Manihot utilissima, Ricinus communis) ', Urticaceae (Sponia 

 virgata) ; Araceae (Arum maciilatum, Colocasia gigantea, Cyrtospernia lasioides, 

 Lasia aculeata) ; Gramineae ( Glyceria aquatica, Panicum, Sorghum vulgare, 

 Stipa hystricina} ; Fungi (Hygrophorus agathosmus, Marasmius oreades, 

 Phaliota radicosa, Russula foetens). He makes the following statement with 

 regard to the presence of this substance in plants : 



"Many plant physiologists in Europe, with more experience with Prunus or 

 amygdalin than with the tropical Pangium, incline to the view that hydrocyanic 

 acid in these plants has nothing to do with either the building-up or the break- 

 ing-down of proteids, but that this substance is made by the plant from sugar 

 and nitrate by a special process, and serves no other purpose than to defend 

 the plants against the attacks of animals. It is above all the incompleteness of 

 our physiological knowledge which makes decision between these theories 

 difficult. 



