518 



THE PARKS AND GARDENS OP PARIS. [Chap. XXX. 



must be removed and carried away to a distance. The cause of 

 this disease is at present uncertain, the opinions of practical 

 Mushroom-growers being divided on the matter. Some at- 

 tribute it to lack of cleanliness when the beds are being 

 broken up. Others say that the remains of old manure mixed 

 with the soil of the quarry generate dampness underneath the 

 beds, and as this moisture cannot be absorbed by the stone surface 

 beneath, it gives rise to the " molle." According to this 

 hypothesis, the remedy would be to thoroughly scrape the surface 

 of the ground on which the bed rests. Others say that the 



Mushrooms attacked by the *'7noUe" — (^Lachaume-') 



" molle " is the consequence of the beds being too much crowded 

 together in a confined space. According to them, the vapours 

 produced by the fermentation of the manure become condensed' 

 on the walls, and, mixing with the natural infiltrations, fall upon 

 the beds, and bring about the decomposition of the manure. 

 They base their opinions upon the fact that it is in the summer, 

 when the heat is great, that the " molle "makes its appearance in 

 quarries with low roofs, and tliat it is much more rare in quarries 

 which have high roofs and strong currents of air circulating 

 through them. But in any case, no matter what may be the 



