PART I 
CHAPTER I 
DEVELOPMENT—THE SPORE, MYCELIUM, AND 
SPOROPHORE 
HE term “ fungi ” includes an immense assemblage of 
X cryptogamic plants, popularly known under the follow¬ 
ing terms: (i) Mushrooms, applied chiefly to the edible field 
mushrooms, Agaricus campestris and A. arvensis , and the 
cultivated form, A. hortensis; (2) Toadstools , agarics other 
than the preceding, all of which are considered to be 
poisonous by the great majority of people in this country; 
(3) Rust, Smut, and Mildew, terms only too well known to 
farmers, applied to minute species which attack cereals, etc.; 
(4) Mould, a term commonly applied to minute species 
infesting various articles of food, ripe fruit, etc., also 
appearing on damp walls, etc. 
The word “mushroom” is probably derived from the 
Old English maes, a field, and rhum, a knob, which became 
mushrhum, and finally mushroom. It is also held to be a 
corruption of the French mouceron or mousseron. We usually 
apply it to the common edible species, A. campestris; the 
French apply it to the St. George mushroom, Tricholoma 
gambosum. Mycology, as the study of fungi is termed, is a 
word derived from the Greek makes, apparently a species 
of mould, and logos, a discourse. 
Fungi are closely related to algae and lichens. They are 
descended from the former, and enter into the composition 
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