184 DICTIOIJ^AEY OF POPULAR NAMES FUNGI 



stools, wMch. include the numerous species of tlie Mushroom 

 tribe ; it also includes a number of microsopic bodies, suck as 

 mildew, moulds, dry-rot, etc., wMcb grow on living but more 

 abundantly on decayed animal or vegetable matter. They are 

 important factors in reducing all organised bodies to their 

 original elements. The number of so-called species may be said 

 to be beyond calculation ; indeed, it seems as though new forms 

 spring into existence according to the nature of the substance 

 upon wMch they grow ; they almost appear to be organisms of 

 chance, many coming into existence and living only a single night. 

 According to the Eev. M. J. Berkeley, the greatest modern writer 

 on this family, the number of species (so called) amounts to about 

 4000, of which 2380 are natives of Britain. They are found in 

 all countries and situations where animal and plant life exist ; 

 they not only grow on lofty trees, in dry pastures and buildings, 

 but also in mines, cellars, drains, and stinking ditches. Fenicilliwn 

 glaums is the blue mould of cheese, jeUy, preserves, and woyeu 

 fabrics when long damp ; the iron mould (so called) on linen is a 

 kind of mildew. The most formidable, however, are the potato 

 murrain, grape mildew, dry-rot, smut, coffee and salmon disease, 

 all caused by microscopic species. Fungi are the sole agents in 

 fermentation of sugary hquids, and it is found that yeast, which 

 causes dough to rise, is a fungus. Many such — as mushrooms, 

 morells, and truffles — are wholesome and delicious food, while 

 others are poisonous in the highest degree ; many of the latter, 

 being similax to and taken for the true mushroom and used as 

 such, have led to fatal results. Tungi are reproduced by spores, 

 which are so numerous that in the puff-ball when ripe and 

 pressed they are seen to rise in the air like smoke ; but to 

 determine then: size and form requires the aid of a powerful 

 microscope. They float in the air, and alighting on substances con- 

 genial to theic development and growth, they thus become spread 

 in different localities. Those that emanate from foul cisterns, 

 water-closets, and drains, are now considered to be the actual 

 cause of contagious diseases, such as typhoid and scarlet fever, 

 cholera, and even diphtheria. It has been proved that milk 



