GUIDE TO THE MODELS OF FUNGI. 



33 



and destroys mushroom beds. Its growth in the mycelium condition 

 within the beds resembles very thick, black string, and this has 

 sometimes been so abundant that many barrow-loads have had to 

 be removed. If this be placed upon or buried in garden beds, it 

 will often grow freely, and injure or even kill garden plants. 



Like other plants, mushrooms are subject to disease, and diseased 

 mushrooms are quite as likely to prove poisonous as diseased meat. 

 Many microscopic moulds attack mushrooms, and no mushroom in a 

 mouldy condition is fit for food. Mushrooms are frequently attacked 

 by a disease in which the gills become very much thickened or 

 totally obliterated ; this is brought about by the attack of a parasitic 

 fungus named Mycogone alba Letell., a stage in the development of 

 a species oi Hyponiyces (see model of//, latcritiits). Mushrooms are 

 frequently sold in the markets in this condition ; the mycelium 

 thoroughly permeates the whole plant, and no doubt such mush- 

 rooms are dangerous if used as food. 



Even perfectly sound mushrooms sometimes produce unpleasant 

 symptoms. In the Gardeners Chronicle for November 5th, 1881, the 

 Rev. M. J. Berkeley records several cases of diarrhoea, one of great 

 severity, from eating mushrooms. He says : " My remark in this 

 and other cases of supposed poisoning with undoubtedly good mush- 

 rooms, is simply that the persons who gather them return hungry 

 and fatigued, the mushrooms are badly cooked and hastily swallowed, 

 so that they are irritating, tough, indigestible masses in the in- 

 testines. When properly masticated they are, on the contrary, 

 perfectly wholesome." Cases of diarrhoea are not uncommon, and 

 have been noticed with regard to Boletus edulis and other species. 



An excellent ketchup is made from A. campestris, but very few 

 mushrooms are apparently used in the " mushroom ketchup " of 

 commerce. Home-made ketchup is seen under the microscope to 

 be full of mushroom spores, but an examina- 

 tion of the mushroom ketchup of commerce 

 discloses as a rule very few spores, in some 

 noneat all, and in others the spores of worth- 

 less Coprini. 



Sub-genus 22. Stropharia. — There 

 are eighteen British species of Stropharia, 

 only two of which are illustrated by models. 

 Stropharia agrees in structure with Armil- 

 laria and Pholiota ; but the spores are 

 purple, not white or brown. In Stropharia 

 the gills are adnate and the veil annular. 

 The species grow on the ground, dung, or Fig.^e.-Typef^nTofStTpharia 



stumps : none are edible. Agaricus aeruginosus Curt. 



(One-third natural size.) 



60. Agaricus aernginosus Curt. — Pileus glutinous, bluish-verdi- 

 gris in colour, and flecked with white superficial scales, the colour 

 being in the tinted slimy pellicle, which is soon washed off in wet 



3 



