522 THE L'AKKS AND GARDENS OF PARIS. [Cuav. XXX. 



4. The Grey Mushroom. This variety attains the largest 

 l^roportions of any. Its cap sometimes measures ISf in. in 

 diameter, the open portion near the stem being as much as 4^ in. 

 across. The skin of the cap is greyish buff, and is generally torn 

 into silky filaments. The stem is about 2 in. high, and 1| in. in 

 diameter ; the ring is highly developed, and conceals the gills 

 when the edges of the cap are open. The flesh is very firm, 

 remarkably white, and emits a rich odour. In spite of these good 

 qualities, this kind is less sought after than the others. 



These varieties are pretty constant when grown under the same 

 conditions, but I have seen spawn of the cream-coloured variety, 

 when sown in a quarry, yield Mushrooms of the pure white 

 variety, which would seem to indicate that the conditions under 

 which they grow have a great influence. To be certain of the 

 variety we are cultivating, we must grow successively two crops 

 from virgin spawn, so as to leave the soil and the nature of the 

 manure suflicient time to exercise their influence. For instance, 

 virgin spawn grown on pigeons' guano may, when a bed is first 

 sown with this spawn, give a white or cream-coloured Mushroom, 

 but the virgin spawn, grown on the same bed, having been 

 influenced by the horse-manure, may produce a variety at the 

 second crop. 



In his little work on the ' Culture of the Mushroom,' M. La- 

 chaume gives a description of a method of growing Mushrooms 

 without manure, which he has adopted with great success. He 

 takes a cubic yard of old lime-rubbish, and reduces it to frag- 

 ments the size of a Hazel-nut. The mass is then moistened and 

 transferred to a dark cellar. This mass, from containing large 

 quantities of nitrous salts, greatly favours the development of the 

 Mushroom. Against the wall a sloping bed is made with the lime- 

 rubbish about two feet three inches wide, and two feet high, the 

 lower edge being kept in its proper place by means of thin boards. 

 The surface is then smoothed with the hand, and pieces of spawn 

 are inserted all over the bed, at eight inches apart. The sowing 

 being completed, the whole is covered with river-sand or fine 

 stone-dust to the depth of an inch and a half. The sand should 

 be fresh, and not too damp, but as soon as the surface of the bed 

 becomes dry it should be lightly watered with a solution of salt- 

 petre, two ounces to the gallon. The beds must be watered with 



