214 Transactions of the [Sess. 



exosmose. By tlie double process of absorption and elimination 

 the phenomena of nutrition, assimilation, growth, and by-and-by 

 of reproduction, are accomplished. At maturity the plant gives 

 forth seeds like other vegetables, and their emission immediately 

 arrests development. Some species arrive at maturity in a few- 

 hours. Thunderstorms favour their appearance. Mushrooms being 

 found after such storms in places where there were no traces of 

 them the day before. Coprini are very ephemeral, withering after 

 a day's existence. Fleshy species last from six to twelve days, and 

 some of the Polypori live for several years. 



In discriminating species, the chief points to be attended to are 

 the form of the gills, their mode of attachment to the stem, their 

 colour, and more especially the colour of the spores. The colour 

 of the pileus, the form and characteristics of the stem, are so 

 variable often in the same species as to mislead and perplex the 

 student. The preservation, too, of Fungi is exceedingly difficult — 

 some fade so rapidly, melting almost before your eyes. Even the 

 tough species, when cut into sections and dried, become unrecog- 

 nisable in a few weeks. A fairly satisfactory plan of preserving 

 the beauty of these interesting plants (which I hit upon rather 

 late, however, for the most of my collection this autumn) is to dip 

 them in melted paraffin. Care must be taken not to allow the 

 paraffin to get too hot, and so injure the specimens by burning 

 them. To get a thin and equal coating all over your specimen, 

 the process must be carefully done. Some specimens now exhib- 

 ited have been preserved in this manner for about two months, 

 and if kept in a dry spot, it is reasonable to expect that they will 

 remain in this condition for years. 



This autumn I collected nearly forty species round Edinburgh. 

 In the Meadows I gathered Coprinus comestus, Agaricus campestris, 

 A. cristatus, A. fcenisecii, and A. rimosus. On Arthur's Seat I found, 

 besides, A. albocyaneus, A. umbelliferus, A. dealbatus, A. ceraceus, 

 Hygrophorus psittacinus, Lepiota excoriatus, and Boletus luteus. 

 In Corstorphine Woods, Agaricus fascicularis, A. cinnamomeus, A. 

 variabilis, A. dryophilus, A. semiglobatus, A. radicatus, Hygropho- 

 rus conicus, H. virgineus, and Lepiota granulosus. In Greyfriars' 

 Churchyard I got Coprinus micaceus and Agaricus cortiles ; and 

 in gardens and nurseries in town I found Coprinus aliamentarius, 

 Agaricus pratensis, A. velutipes, and Lactarius rufus, besides 

 others I have not been able to identify. 



The uses of the Hymenomycetes, though perhaps not of great 

 importance, are both numerous and varied. Many species of this 

 family are employed as food. The Dutch, who think that the 

 devil gets the best of everything in this world, call them the 

 devil's bread. Only one species, Agaricus campestris, the common 

 Mushroom, is looked upon with favour in this country, and yet it is 



