Chap. XXX.] MUSHROOM-CULTURE IN CAVES UNDER PARIS. 517 



the spawn from a young bearing-bed is just when the young 

 Mushrooms are first appearing. The bed thus selected is 

 broken up, and the cakes of spawn removed, and broken into 

 lumps of about the size already described. This kind of spawn 

 is in the best condition for yielding an early and abundant crop 

 of Mushrooms, which may be gathered at least twenty days 

 sooner than if dry spawn had been used. 



To soil a mushroom-bed, the Paris growers use the chips and 

 powder of the stone which has been taken out of the quarry, and 

 which may be procured in large quantities either on the floor of the 

 quarry or on the surface of the ground around the shaft. This 

 rubbish is passed through a sieve, and the finer portions mixed 

 with light, dry earth, in the proportions of three of the former 

 to one of the latter. The mixture is then watered so as to form 

 a dry putty-like paste, in which the fingers will leave an im- 

 pression. The addition of the earth to the powdered stone favours 

 the development of the Mushroom. Great care must be taken in 

 selecting the cakes of spawn, only those flakes being chosen which 

 show an abundance of bluish-white filaments well knitted to- 

 gether and having a characteristic odour of Mushrooms. 



Among the spawn may sometimes be found a spurious kind, 

 which must be avoided. Such patches are a kind of fungoid 

 growth which spreads very fast, an almost imperceptible spot being 

 sufficient to infect and kill a large quantity of healthy Mushrooms. 

 This disease the French growers call la molle, or la mole. As 

 will be seen by the illustration, the Mushroom when attacked by 

 this disease loses its shape, and forms a spongy mass full of 

 granules. The skin which covers this shapeless cottony mass is 

 pure white at first, but speedily changes to a yellowish-brown as 

 it rots away. It emits a disgusting odour, and the inside becomes 

 filled with brown threads, which are sure signs of decomposition. 

 Sometimes the edges of the cap turn upwards instead of down- 

 wards, and the gills become united into a spongy mass which 

 sticks to the edges of the cap. As soon as the diseased Mushroom 

 comes into contact with the air it turns brown, and exhales an 

 odour like that of putrifying meat. When the disease shows 

 itself in only a few isolated cases, the Mushrooms attacked are 

 promptly removed from the beds and quarry ; but if it has 

 been allowed to spread, the whole of the bad and diseased spawn 



2 M 



