Sketch of the Class Fungi. 



Ill 



posing a net by their frequent anastomoses. A very thin slice 

 plac ed under the microscope shows that the inner layer of the walls 

 of these cavities is composed of obtuse, pellucid cells, placed parallel 

 to each other like the pile of velvet, exactly as in the hymenium 

 of a young Agaric. At a later period Mr. Berkeley has seen four little 

 spicules of equal length spring from the tips of the basidia, named 

 by him sporophores, and on each of these at length appeared a 

 globose spore. The shrinking of the basidia induces the pulpy state 

 of the Lycoperdon preceding maturity, which is indicated by its 

 pulverulence. At this period, all the moisture contained in the in- 

 terior of the peridium being absorbed, either because the juices 

 which made it succulent and fleshy have performed their functions 

 of nutrition, or from some cause independent of the morphosis, the 

 sporophores or basidia shrink, wither, dry, and remain under the 

 form of confervoid filaments. The sporidia having become free are 

 intermixed with the filaments, and bear still the thread by which 

 they were fixed to their summit. The same observations have been 

 made upon Geaster, and Corda {I. c. ii. p. 24. t. 12. f. 90.) has 

 figured something analogous, if not quite similar, in his genus Pty- 

 chogaster. This singular morphosis, which brings the order of 

 Lycoperdinea near to the true Hymenomycetes, had been already ob- 

 served by Vittadini*, who, from not having followed it in many 

 species, still less in many groups, could not, as Mr. Berkeley has 

 done, draw from it any general systematic conclusions. 



Having seen what takes place in the normal evolution of Lyco- 

 perdons, let us review the principal forms assumed by the peridium 

 in the series of genera, its texture, mode of rupture, and finally the 

 organs of fructification which it is destined to contain. But first I 

 would premise, that there are in this order genera whose peridium 

 is developed on the surface of the soil {emergens), others in which it 

 is not seen till it has acquired a considerable size under the surface 

 of the earth {innato-emergens) , and some are altogether subterraneous. 



The trama of the peridium is formed by the interlacing of the 

 filaments of which the fungus is at first entirely composed. It is 

 formed either of a single coat of byssoid fibres {Tulostoma, Lycoper- 

 don), or of two coats often only slightly adherent, and of which the 

 outer one falls at maturity (Bovista). In the Geastra, where these 

 two coats are very dissimilar, we may consider them as two peridia, 

 of which the outer f, which is coriaceous or tuberculated, splits from 

 the top towards the base to a greater or less extent into several rays 

 or laciniae, expanded like a star, or recurved, and contains from the 

 beginning the first which is sessile, uni- or pluristipitate {Geaster 

 coliformis), always thin, membranous or papyraceous. 



In a single exotic genus Mitremyces, where the peridium is like- 



* Monog. Tuberac, p. 20 and 83. t. 5. f. 9 e. 



t In Geaster triplex, Jungh. (Tijdschr. voor natur. Geschied. en Physiol. 

 2-3 Stuck, 1840. t. 8. f. 1, 2, 3) the outer peridium is composed of two 

 separable layers, of which the inner forms a broad cup, and the outer is 

 divided regularly into recurved laciniae. 



