6 INTRODUCTION 



The taste of the majority of the Basidiomycetes when raw is 

 watery-insipid ; many are practically tasteless or mild. Some when 

 uncooked have a pleasant nutty flavour, as Psalliota campestris 

 (mushroom) and Lepiota procera. Several are bitter, as Boletus 

 felleus ; others are bitter-nauseous, as Hypholoma fascicttlare, and 

 many species of Lactarius and Russula are very acrid or bitter 

 acrid. 



The odours are most diverse. Clitocybe fragrans is very sweet 

 and recalls Melilot, as does also Hydnum graveolens ; C. odora is 

 fragrant of Woodruff or Vernal Grass ; Trametes sitaveolens, T. 

 odora, Lactarius glyciosmus and Clavaria stricta are also very sweet- 

 scented. One variety of Cantharellus cibarius smells strongly of 

 apricots, and Clitocybe geotropa is almond-scented. Many smell 

 strongly of onions or garlic, the best known examples being 

 different species of Marasmius. Fetid and disgusting odours are 

 common ; a familiar instance is that of Ithyphallus impudicus. The 

 odours possibly serve some purpose at present unknown. The 

 carrion-scented species attract swarms of carrion-feeding insects 

 which greedily devour the highly fetid, soft, sporiferous material 

 of the Phalloidacece. 



The exudation of fluid, the so-called milk, when the stem is 

 broken, is a remarkable character of some species. Mycena galopus 

 and M. lactea contain a white, M. crocata and M. ckdidonia a yellow, 

 M. hcematopus a dark purple-red, and M. sanguinolenta a red juice ; 

 Lactarius deliciosus exudes an orange-coloured and L. sanguifluus 

 a deep blood-red juice which, on exposure to the air, quickly 

 becomes green. The milk of L. chrysorrheus and Z. theiogalus is 

 sulphur-yellow, that of Z. acris is at first white, then reddish. The 

 milk of Z. uvidus is white and quickly changes to violet ; that of 

 Z. scrobiculatus is first white, then sulphur ; that of Z. fuliginosus is 

 white, then saffron. The stem of Marasmius varicosus is filled with 

 dark blood-red juice, which flows when the stem is bruised or 

 broken. 



Some species of Agaricacece, as Hypholoma lacrymabundum and 

 H. velutiuum, have " weeping gills " ; in mature examples drops of 

 fluid may be seen sprinkled all over the surface of the gills which, 

 when examined under the microscope, are seen to be charged with 

 spores and cystidia. The hymenium of the dry rot fungus, Merulius 

 lacrymans, is usually covered with globules of exuded moisture ; 

 Polyporus dryadeus is often seen in the same condition. 



The Basidiomycetes as a rule do not exhibit brilliant colouring, 

 but there are remarkable exceptions, the most striking being scarlet 

 and crimson, as in Amanita muscaria. Yellow, orange, blue, purple, 

 and white also occur, also rarely green and black, but the majority 

 are pallid, watery-brown, brown, greyish or buff. The brown and 

 buff colours of Agarics often cause the fungi to be overlooked when 

 growing amongst dead leaves. 



The Mushroom is a highly nitrogenous plant and contains a con- 



