302 THE GRAY RAT. 



medium of their parasites, or even by the con- 

 tamination and filth of their own persons. 



In this connection it may be as well to reiterate 

 the fact that research has resulted in the discovery 

 that the terrible bubonic plague, which at times 

 reaches such horrifying dimensions in India and 

 China, is communicated by rats to human beings 

 by the medium of the rat flea, and it must be 

 borne in mind that so long as rats remain with us 

 in their present numbers we ourselves are assured 

 no immunity. The plague is nature's plan of 

 keeping the rat multitudes in check otherwise 

 they would overrun the whole earth and the flea 

 is nature's means of spreading the disease from rat 

 to rat. Incidentally, it is also the instrument by 

 which the infection is spread from rat to man. 



Deaths from this plague in India alone reach 

 many millions periodically, and occasional outbreaks 

 of it occur in Britain, generally in our big seaport 

 towns, where rat-infested ships come to harbour. 

 Rats suffering from plague have been caught in 

 England, and if once the epidemic got moving in 

 earnest it would be virtually impossible to check 

 it. Since 1914 rats have increased enormously in 

 numbers, and here and there the rat population 

 must already be so dense that the animals can 

 be regarded as living ' under unclean conditions,' 

 which in the case of the rat means disease. 



As regards the material damage actually done 

 by rats the destruction of valuable materials that 

 is taking place in every village and town of the 

 British Isles one needs only to picture the loath- 

 some hordes to be seen swarming forth at the fall 

 of dusk from every suitable harbourage where food 

 for them exists. Rick-yards, knackeries, slaughter- 

 houses, warehouses, docks, stores, sewers, shops 



