NATURE OF FUNGI. 15 



be made are principally minute fungi ; and as 

 it is impossible to comprehend their action 

 upon the several parts of the wheat plants 

 without some general knowledge of their 

 nature and habits, it will be necessary to occupy 

 a few pages with a description of them. Fungi 

 belong, botanically speaking, to the class of 

 thallogens, of which there are three aUiances 

 well described in Lindley's Vegetable King- 

 dom. These alliances are algcBy fungi^ and 

 lichens. The first live in water, or very moist 

 places : the last two live in air. Between fungi 

 and lichens the chief distinction is that fungi 

 are never accompanied by any of those curious 

 green gonidih* or separated cellules of the 

 medullary layer of the thallus, which, as well as 

 their spores or seeds, form reproductive matter 

 in lichens. Suppose, then, the question asked. 

 What is a fungus? The answer is, it is a 

 cellular, flowerless plant, deriving its nutriment 

 by means of a thallas, to which the name has 

 been given of mycelium^ or spawn : it lives in 

 air, and is propagated by spores, which are 

 naked, or by sporidia, so called when inclosed 

 in ascit or little vesicles. The way in which 

 these spores germinate, generally speaking, is 



* Derived from ynvfj {gone) offspring, or that 

 which begets seed. 



