336 



writings of Nees von Esenbeck, and to the Scottish Cryptogamic Flora of 

 Dr. Greville. 



Geography. The Fungi by which most extra-tropical countries are 

 inhabited are so numerous, that no one can safely form even a conjecture as 

 to the number that actually exists. If they are ever fortuitous productions, 

 the number must be indeterminable ; if many are mere diseases and the re- 

 mainder fixed species, then the knowledge of their nature must be reduced 

 to a more settled state before any judgment upon their number can be formed. 

 According to Fries, he discovered no fewer than 2000 species within the 

 compass of a square furlong in Sweden ; of Agaricus alone above 1000 species 

 are described ; and of the lower tribes the number must be infinite. Sprengel, 

 however, does not enumerate in his Systevia Vegetabilium more than between 

 2700 and 2800 ; but when we consider that his genus Agaricus does not go 

 beyond number 646, although 1000 at least are described, it is not improbable 

 that the rest of his enumeration is equally defective, and that the number of 

 described Fungi perhaps amounts to between 4 and 5000. Of tropical species 

 we know but little ; their fugitive nature, the difficulty of preserving them, 

 and perhaps the incuriousness of travellers, as well as their scarcity in the 

 damp parts of equinoctial countries, have been the causes of the proportion 

 in such climates between Fungi and other plants being unknown. 



Properties. A large volume might be written upon the qualities and 

 uses of Fungi, but in this place they can be only briefly adverted to in a very 

 general way. They may be said to be important, either as food or as poison, 

 or as parasites destructive to the plants upon which they grow. As food, 

 the most valuable are the Agaricus campestris, or common Mushroom, the 

 various species of Helvella or Morel, and Tuber or Truffle; but a consider- 

 able number of other kinds are used for food in various parts of the world, 

 of which a useful account will be found in Decandolle's excellent Essai sur 

 les Proprietes Medicales des Plantes, in Persoon's work "Air les Champignons 

 comestibles, and in a paper by Dr. Greville in the 4th volume of the 

 Transactions of the Wernerian Society. 



It is necessary to exercise the utmost care in employing Fungi, the 

 nature of which is not perfectly well ascertained, in consequence of the 

 resemblance of poisonous and wholesome species, and the dreadful effects 

 that have followed 'their incautious use. It is true that many kinds are 

 named by Pallas as being commonly used by the Russians, which are 

 plentiful in countries where they are not employed for food ; but, in the 

 first place, it is not perhaps quite certain that poisonous and wholesome 

 species are not confounded under the same name ; in the next place, 

 climate may make a diflPerence ; and lastly, much depends upon the mode 

 in which they are cooked. Upon this subject Delile observes, that it was 

 ascertained by M. Paulet, in 1776, that salt and vinegar removed every 

 deleterious principle from that most poisonous plant the Agaricus bulbosus; 

 that it is the universal ])ractice in Russia to salt the Fungi, and that this 

 may be the cause of their harmlcssness, just as the pickling and subse- 

 quent washing of the poisonous Agaric of the Olive renders it eatable in 

 the Cevennes ; but that nevertheless it is much wiser to run no risk with 

 unknown F'ungi, even taking such precautions ; a remark to which he 

 was led by the lamentable death of a French officer and his wife, in conse- 

 quence of breakfasting off" some poisonous Agarics, which were nevertheless 

 eaten by other persons in the same house with impunity. It was probable 

 that in that case a difference in the cooking was the cause of the 

 difference in the effect of the Fungi ; but it was a sufficient ground for dis- 

 trusting all Fungi except the cultivated ones. So strongly did the late 



