Sketch of the Class Fungi. 



291 



The hymenium whose structure I have just described covers the 

 two faces of the gills of Agaricini, and the whole surface of the 

 prickles in Hydna, by being reflected upon the hymenophore in the 

 interval which separates them ; penetrates into the interior of the 

 tubes or pores of Polypori, clothes the whole surface of Auricu- 

 la rini, and the upper surface only of Clavarice, and extends finally 

 into the sinuosities of Tremellini, with the gelatinous substance of 

 which it is frequently confluent. 



The Hymenomycetes are fungi which flourish and increase most 

 abundantly in temperate climates. Nevertheless, even under the 

 tropics, where the negligent manner in which they have been looked 

 for has induced a supposition that they are more rare than they 

 really are, there are certain localities in which their number and va- 

 riety are not less than with ourselves. Besides, in Europe, their de- 

 velopment is subordinate to the seasons, and the greater number 

 appear only in autumn, the most favourable time for their growth, 

 because of the joint heat and moisture. In equatorial countries, on 

 the contrary, according to Junghuhn (Communic. sur Java, Ann. 

 Sc. Nat. Bot., 2 ser., torn. vii. p. 170), besides that the species 

 of this family are at least as abundant* as in our climate, their re- 

 production goes on during the whole of the year. M. Leprieur has 

 observed the same fact in Guiana. With us the summer and au- 

 tumn are the seasons which favour and expedite the evolution of the 

 greatest number of Agaricini, Polypori, &c. Spring is less propi- 

 tious, and winter produces a few rare species only of these tribes. 

 Amongst Hymenomycetes, some are common to a great many coun- 

 tries, others are found only within certain limits (e. g. Ag. olearius, 

 Pol. Tuberaster) ; some, amongst which it is remarkable that we must 

 reckon Ag. campestris, the only species eaten at Paris, are cosmo- 

 polites. Schizophyllum commune is also of this number. 



Fungi of this family flourish especially on wood, at the foot of 

 trees or on the trunk, on dead or rotten wood, on dry branches 

 fallen on the ground, on living mosses, and in general on all or- 

 ganized, diseased, or dead bodies. We find them likewise in fields 

 and meadows. They grow solitary or grouped together (gregarii), 

 or united into a mass (caspitosi). Sometimes they form by being 

 disposed in concentric circles, what were named fairy rings, because 

 people were absolutely ignorant of the cause of their production. 

 Perhaps we are as ignorant at the present time as to the ultimate 

 cause ; but if I mistake not, we may give a plausible explanation of 

 the proximate cause, that is to say, of the concentric disposition of 

 the circles. This appears to result from the circular dispersion of 

 the spores of the preceding year, perhaps also from the eccentric 

 vegetation of the mycelium ; that is to say, outside the last circle 



* They are probably much more so in proportion to the whole number 

 of species. In Junghuhn's ' List of Fungi of Java,' given by Dr. Montagne 

 in Ann. Sc. Nat. Nov. 1841, out of 113, 66 are Hymenomycetous ;. and 

 the proportion is still greater in a collection made by Cuming in the 

 Philippine Isles. — M. J. B. 



