112 TRANSACTIONS, NATl'RAL HISTORY SOCIETY OF GLASGOW. 



(Zingiberaceae), pungent or peppery seeds are 

 obtained. 



The fruits of the guelder-rose, honeysuckle, ivy, 

 dog-mercury, Lobelia, and some of the Scrophulari- 

 aceae, possess emetic properties, so that in the event 

 of the seeds being swallowed there is a possibility 

 of their being vomited up again. 



Most succvilent fruits, such as the fig and tamarind, 

 have a laxative tendency. Many again act as power- 

 ful purgatives, e.g., Citrullus Colocynthis, the coloc.>Tith 

 (Cucurbitacese) ; lyomoea Purga, jalap (Convolvula- 

 ceae); numerous Euphorbiacese, such as Euphorbia 

 Lathy r is, Crofon Tiglium, Ricinus communis (castor- 

 oil plant), and Jatropha Curcas, (physic-nut) ; Rhatn- 

 nus catharticus (Rhamnacese) ; Broimis ccitharficus and 

 R. purgans (Graniinese). Emetic and purging seeds 

 are not likely to remain long enough in an animal's 

 stomach to admit of their germinating power being 

 destroyed. 



Narcotic and poisonous properties are not vmcom- 

 mon in seeds and fruits. We have marked instances 

 of this in Atropa, Hyoscyamus, Andromeda, Strychnos, 

 and in some of the Apocynacese and Umbelliferse. 

 A seed which occasions the death of any animal 

 that swallows it might be benefited by its poisonous 

 properties if the rich soil furnished by the decaying 

 body of its victim were necessary for its germination. 

 But it is hardly probable that this can be the end 

 intended in all poisonous seeds. If any plant were 

 systematically to poison the birds on which it 

 depended for dispersion, one of two things must 

 happen. Either this short-sighted policy would lead 

 to the extermination of its benefactors, or the birds 

 would gradually learn to avoid the fruits. In any 

 case the plant would lose its means of dissemination, 

 and place itself at such a disadvantage in the com- 

 petition with other species as would in the long run 

 lead to its own extinction. Further, it must be 

 borne in mind that substances poisonous to man 

 and certain animals are without effect on certain 



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