AN ENCYCLOPAEDIA OF HORTICULTURE. 



395 



Mushrooms continued. 



over fleshy, tapering outgrowths, or teeth, on the lower 

 surface of the cap; in Boletus and Polyporus, the sur- 

 face is formed by reticulately-joined ridges, that leave 



FIG. 610. COMMON MUSHROOM (AGARICUS CAMPESTRIS). 



tubes, or pores, between them ; in Craterellua, it is 

 smooth, or merely wrinkled. Mushrooms vary exceed- 

 ingly in colour, the upper surface of the cap usually 

 showing more decided tints than the stalk. Many are 

 white ; others yellow ; others red in various tints ; others 

 show shades of grey or brown, at times almost passing 

 into black. A smaller proportion are some shade of blue, 

 or of metallic green ; but they do not show a pure leaf- 

 green, dependent on the presence of chlorophyll, since 

 they never contain this substance. The surface 

 of the cap is usually smooth; it may be sticky, 

 hairy, warty, &c. Some species change colour, at 

 once or gradually, if any part is broken. This is 

 peculiarly noticeable in some kinds of Boletus, in 

 which the bruised surfaces become an intense blue. ^ 

 The change to blue is to be regarded as a sign 

 that the Mushrooms which show it are poisonous 

 or suspicious in their properties. The smell of 

 Mushrooms is slightly peculiar, and is usually not 

 difficult to recognise, there being in it something 

 that reminds one of a closed, mouldy vault or 

 cellar. In decay, most of them emit a strong 

 nitrous smell, some have a most disagreeably 

 foetid stench, but others are rather pleasantly 

 scented, like newly dried hay. A curious pro- 

 perty of some Fungi is the luminosity they display. 

 In some kinds, the light is so strong that, in dark 

 places, the plants can be seen from a considerable 

 distance. This phenomenon is manifested by spe- 

 cies in various groups of Fungi; but the most 

 striking examples are met with in the genus 

 Agdricus, several members of which have been 

 observed to be luminous, apparently in the healthy 

 state. In some, the cap and stalk emit light ; but 

 more frequently the mycelium in decaying wood is 

 the luminous part. Another characteristic of some 

 Mushrooms e.g., the genus Lactarius and several 

 species of Agaricus is the appearance, on broken or cut 

 surfaces, of a milky fluid the latex which pours out 

 from long tubular cells in the tissues of the plant. This 



Mushrooms continued. 



fluid may be white, yellow, or orange ; and, at times, 

 changes colour after being exposed to the air for a 

 short time. In some cases, the latex has a pleasant 

 taste, while, in others, it is very acrid. Mush- 

 rooms, like Fungi in general, are propagated 

 by means of spores, which, as already men- 

 tioned, are borne on large cells (basidia), pro- 

 duced on the hymenium. These spores can be 

 obtained by laying the Mushrooms, gills down- 

 HP;, wards, on paper, which should be of a tint to 

 -^^^ contrast with them in colour. They will be 

 ^pr / found to map out on the paper the arrange- 

 =5^' / ments of gills or pores, and, in this way, their 

 / colour in mass also can be easily detected. 



The colour of the spores is largely employed 

 in breaking up the very large genus Agaricus 

 into sub-genera of more convenient size. 



Uses, Mushrooms and their allies include 

 almost all the Fungi that can be regarded as 

 of direct use to man as food-plants. A con- 

 siderable number have been, or are, used in 

 diet, either because of the amount of nitro- 

 genous matter in them, or as imparting a 

 pleasant flavour to the articles with which 

 they are served at table. But, while it is 

 comparatively easy to recognise certain of the 

 well-known edible Mushrooms, great care is 

 required to prevent serious results when poi- 

 sonous species are gathered by mistake, and 

 eaten with the useful ones. Such a mistake 

 is not infrequent, since a very great resem- 

 blance exists between certain poisonous and 

 edible kinds. The Mushroom most generally 

 esteemed in Britain is the Common Mushroom (Agaricus 

 campestris, see Fig. 610). It is so well known as scarcely 

 to caU for a detailed description of its appearance. It is 

 largely cultivated, but it is also frequently abundant in 

 pastures, especially in natural grass land or meadows. 

 At first, the gills are pale pink, or salmon-tinted, but they 

 deepen into a peculiar purplish-brown. The upper surface 

 of the cap varies somewhat in colour and smoothness, and 

 there is a permanent ring of tissue around the stem, a 



FIG. 611. ST. GEORGE'S MUSHROOM (AGARICUS GAMBOSUS). 



little way below the cap. This Mushroom does not enjoy 

 the same high reputation on the Continent of Europe that 

 it possesses among ourselves ; and, in Italy, it is said to 



