PREFACE 



AS in the case of a previous volume. Common Weeds of the Fa/rm 

 -^^ and Garden, the preparation of this handbook was undertaken 

 because of the great lack of readily available and reUable information 

 on the subject in Enghsh scientific literature. Many of the facts were 

 known to a few interested persons, but many others were so scattered 

 here and there in technical reports and journals that they were scarcely 

 known even to expert chemists and botanists. The bringing of this 

 information together in some sort of order has involved considerable 

 labour extending over several years, but if the volimie be found helpful 

 to those for whose use it has been prepared I shall feel more than 

 gratified. 



That the subject is of importance is fuUy reahsed by farmers and 

 veterinary surgeons alike, for the annual loss of stock due to poisonous 

 plants, though not ascertainable, is undoubtedly considerable. It was 

 felt that notes on mechanical injury caused by plants and on the 

 influence of plants on milk might usefully be included, as in some 

 degree related to poisoning; this has therefore been done. On the 

 other hand, a number of cultivated plants {e.g. Rhus, Wistaria) which 

 are poisonous have not been included because exotic and hardly likely 

 to be eaten by stock. Fungi generally also find no place in the volume, 

 as they are sufficiently extensive to deserve a volume to themselves, 

 and are far less readily identified than flowering plants. 



The dividing line between plants which are actually poisonous 

 and those which are only suspected is far from clear, but a division 

 was considered desirable for the convenience of the reader, and an 

 endeavour has been made to give a sound but brief statement as to 

 the present information on plants poisonous to five stock in the United 

 Kingdom, with symptoms, toxic principles, and a list of the more 

 important references to the bibhography in relation to each plant 

 included in Chapters n to vi (the numbers corresponding with the 

 numbers in the Bibhography). 



Begarding sjrmptoms it is to be regretted that in many cases they 

 appear to be the result of injections of the toxic extracts, and not 

 observations made after natural poisoning by ingestion of the plants. 



