FUNGI. 



355 



as we ought to have upon so important a point. There are nearly 



3,000 species reputed to belong to Great Britain ; so after making a 



reasonable allowance for a multiplication of species, there remains a 



larger number than the ordinary horticulturist can be expected 



to master in detail. Some fungi are good articles of food, as the 



mushroom, morel, and truffle, without which no recherche dinner at the 



present time can ever be said to be perfect : others are suspicious, 



and none should ever be eaten unless the name and character of the 



fungus is known. There is even reason to suppose that fungi ordinarily 



eatable, sometimes, from some unknown reason, become poisonous. In 



structure fungi are composed of interlacing longitudinal fibres, which 



always grow from the end, and are divided by septa at right angles 



to the axis. These cells never divide longitudinally ; in fact, the. 



structure consists of closed tubes placed end to end. This structure 



is called the mycelium. After a time, cells are developed at right 



angles to the mycelium, and these produce spores, which generate 



(fig. 122). This is the second method of propagation. Lastly, bodies 



analogous to zoopores are formed, which have the power of moving 



about and attaching themselves to a suitable material, when they 



reproduce the species ; and this is the third mode of propagation. 



The first fungus which is worthy of notice is the ordinary Yeast 

 fungus (Tonda ccrcvisice, fig. 825), which is present in all fermenting 

 liquors. It consists of cells which 

 propagate by other cells forming 

 on their exterior. It is the active 

 organism in the production of 

 vinegar from sugar. It is probably 

 only a condition of the next de- 

 scribed fungus. 



The second fungus which it is 

 important to notice is the Pcni- 

 cillium glaucum, or Blue Mould (fig. 826), which covers most decaying 

 substances. It throws up at right angles to the mycelium heads 

 which are covered with spores. 



A A 2 





FIG. 826. Blue Mo.ild, magnified. 



