NATURAL HISTORY OF THE RABBIT 47 



holds good in the present case, for cure is out of 

 the question ; the only rational treatment being the 

 extirpation and removal of the diseased animals, and 

 the introduction of fresh, healthy stock when the 

 ground, after a dressing of salt and lime, has recovered 

 its pristine freshness, and become wholesome. 



Salt, though not a direct 'plant food,' has an 

 important indirect effect upon the potash, lime, and 

 magnesia in the soil, affecting their decomposition, 

 and rendering them in an available condition to be 

 taken up by the roots ; in other words, salt acts as a 

 purveyor to the plants. Lime, on the other hand, is 

 a direct ' plant food,' and indirectly it acts in many 

 important ways, neutralising poisonous acids, and 

 causing the decomposition of organic matter. The 

 application of these manures, therefore, will be found 

 to increase the amount of herbage considerably. The 

 land should be first dressed with gas lime, say, three 

 tons to the acre, and subsequently with salt, say 

 2 cwt. 



Quite distinct from tuberculous liver is the dis- 

 ease known as 'pulmonary tuberculosis,' caused by 

 the presence in the lungs of a parasitic worm, Stron- 

 gylus commutatus {Filaria pulmonalis of Frolich). 

 Hares as well as rabbits are attacked in this way, 

 but from the observations of M. Megnin it would 



