112 M. C. Montagne's Organographic and Physiologic 



■wise double*, the inner, whose increase does not keep pace with that 

 of the outer, appears to enjoy a sort of elasticity, analogous to that 

 which we observe in Spharobolus , which causes it at a certain epoch 

 to invert itself for the dispersion of the sporidiaf. 



The peridium is simple or compound. In the first case it presents 

 a single ca-\dty, or it is divided into cells or pockets (e. g. Sderoder- 

 ma)X. In the second it encloses a number of partial or secondary 

 peridia {peridiold), within which are enclosed the sporiferous fila- 

 ments (e. g. Polysaccum, CUiciocarpus) . In the emergent species 

 the mycelium furnishes the peridium either with a stem or peduncle 

 (stipes), which is continuous in Mitremyces, only contiguous in Tu- 

 lostoma, or merely with some root-Hke filaments, which are altogether 

 wanting in the subterranean species. The stem itself, sometimes 

 very short and obsolete, is likewise frequently prolonged into the 

 peridium in the form of a columella. This is soft and cottony in 

 Caulog loss urn, hard and woody in Podaxon. 



As regards the dehiscence of the peridium, we have just seen that 

 it is twofold in Geaster. In the emergent genera it mostly takes 

 place towards the summit, rarely laterally (e. g. Cauloglossum) , or 

 at the base, as in Podaxon. It is often regular or irregular in dif- 

 ferent species of the same genus. The irregular mode of rupture 

 takes place by the peridium being torn or broken into scales. The 

 regular dehiscence, which is always observed at the summit of the 

 peridium, consists of an opening sometimes exactly orbicular, obtuse, 

 or surmounted by a cartilaginous border {e. g. Tulostoma mammo- 

 sum) ; sometimes conical, folded and finely striate, or slashed into 

 lacinise ; sometimes plane, cUiate or dentate ; sometimes also piloso- 

 fimbriate (e. g. Lycoperdon). The genera whose species are subter- 

 raneous do not open spontaneously (e. g. Cenococcum). In Geaster 

 coliformis, which seems to result from the normal confluence of 

 several peridia, the single peridium opens by many ciliated orifices. 



The flesh of the fungus is generally white or reddish in this tribe; 

 but after the moq^hosis, which induces pulverulence, the mass of the 

 filaments of the sporidia presents variations of colour in each species. 

 The most common tints are purple-brown, olive, fuliginous with a 

 yellow tinge, cinereous or bluish black, &c. The filaments, which 

 constitute the fleshy mass with which the young peridium is filled, 

 vary likewise considerably in the changes they undergo by the act 

 of vegetation. The two extreme states are their persistence under 

 the form of capillitium (e. g. Lycoperdon), and their complete ab- 

 sorption § {e. g. Cenococcum) . In the multitude of intermediate states 

 there are two worthy of notice ; that where the capillitium, detached 



• Or rather triple, for at the moment of its appearing on the surface of 

 the soil the peridium is enveloped in a hood (calyptra), which bursts circu- 

 larly at its point of attachment to the stem, and falls. 



t Berkeley, Ann. of Nat. Hist. 1839, p. 326. 



+ Messrs. Tulasne, in the paper quoted above, have proved that the struc- 

 ture oiScleroderma is in reality conformable to thatoi' Lycoperdo?i. — M. J. B. 



§ Mr. Berkeley has found filaments mixed with sporidia in Mitremyces 

 coccinea, I. c. t. 7. fig. 1. c. 



