30 OUTLINES OF BRITISH FUNGOLOGY. 



name of Phycomyces ; but this notion is now abolished^ and 

 it takes its place as the prince of these powers of putrescence. 



One of the most curious properties of certain Fungi is their 

 capability of growth in substances which arc in general de- 

 structive to vegetables. Tannin is one of these substances, and 

 yet a Fungus very frequently makes its appearance on the 

 wood with which the tan-pits are lined. It is perhaps not so 

 surprising, that many species prefer spent tan to almost any 

 other substance, though even this does not seem favourable to 

 phaenogams, except so far as it is useful in raising the tempe- 

 rature of the houses in which they grow. Many vegetable 

 poisons, as opium, though innocuous to the plants by which 

 they are produced so long as they remain in their proper cells 

 or receptacles, are positively destructive when mixed with 

 the fluid which is taken up by their roots. More than one 

 species of Fungus, however, is developed on extracted opium, 

 and the factories in India have suffered greatly from their 

 presence. Solutions of arsenic, sulphate of iron, sulphate of 

 copper, etc., though highly concentrated, do not prevent the 

 growth of some Fungi of a low order, though at once destruc- 

 tive to others. A few years since, a little Mould, developed in 

 the solution of copper used for electrotyping in the depart- 

 ment of the Coast Survey of Washington, proved an into- 

 lerable nuisance. Strange to say, it decomposes the salt, assi- 

 milating the sulphuric acid, and rejecting the copper, which is 

 deposited round its threads in a metallic form.^ These pro- 

 ductions, indeed, are sometimes referred to Algee, from their 

 submersed mode of growth; but they are mostly common 

 species of Mould, and very distantly related to Alg<e. 



One of these Moulds is sometimes developed in strong wine, 

 as in Madeira. A Mould, however, of a very different habit 



* Harvey, ' Nereis Boreali- Americana,' part i. p. 6. 



