134 PROTF/TIOX AOATXST ANIMALS. 



poisonous solution ; or a meal prepared and the poison mixed 

 up with it. It is then strewn about in pieces as big as a pea. 



In order as far as possible to prevent the poisoning of 

 useful animals, the poisoned baits must not be placed on the 

 bare ground, but in little cylinders of wood or of grass sods, 

 or in glazed vessels or drain-pipes about IJ inches in 

 diameter, sufficient to allow passage to a mouse. The cylin- 

 ders may be placed on the ground or in the mouse-holes, and 

 must be inspected regularly in order to observe their effects. 

 Glazed vessels are better than drain-pipes, as the latter let in • 

 moisture. 



Phosphorus, owing to oxidation, soon becomes ineffectual in 

 damp or rainy weather. Arsenic is more effective, but less 

 rapid in its action. If either of these poisons is used, the 

 dead mice are generally found lying on the surface of the 

 ground, as they run in search of air and water when feeling 

 the pains of the poisoning. Strychnine and carbonate of baryta 

 kill the mice in their holes after severe convulsions ; it is 

 better to change the bait and the poison from time to time. 



A pest of mice rarely lasts more than 2 or 3 years, as heavy 

 rain, frosts, inundations and disease soon kill them by thou- 

 sands. It would not however be right to wait patiently for 

 such an event to occur, for by timely energetic action the 

 damage may be greatly reduced. 



Attempts were made (as proposed by LoelHer) in 1890, to 

 destroy the mice which were infesting the fields in Thessaly, 

 by subjecting them to a parasitic fungoid disease termed 

 mouse-typhus ; this was communicated to the mice by pieces 

 of l)read which had previously been soaked in water con- 

 taining spores of the fungus. The results in this case were 

 excellent, and it has since been adopted on agricultural lands 

 with success both in France . and Germany. It was also 

 successful in a German forest in 1892-3, on 15 acres, at a 

 cost of 5s. G(/. per acre. 



4. Treatmeut of Injured PlautH. 



Broad-leaved poles and saplings which have been badly 

 gnawed by mice should lie cut-back in tlie spring close to the 



