INTRODUCTION TO CRYPTOGAMIC BOTANY. 291 



ing object. In other cases the stem is so confluent tliat thus 

 we have forms, as Geoglossum difforme, not distinguishable 

 from true HymPMomycetes except by their mode of fructifi- 

 cation. Still, another form or two are produced by the mul- 

 tiplication of the hymenial surface through inequalities which 

 were first shadowed out in Peziza venosci, and these in the 

 common morell are increased to such an extent as to repre- 

 sent deep pits like those of a honeycomb. 



801. There is a lower series, where the cup is obliterated 

 simply by expansion, the attenuation of the margin, and the 

 flattening of the hymenial surface. Such forms are represented 

 by Propolis and Gryptomyces. The change from the cupulate 

 to the clavate form takes place in two directions from Peziza; 

 first, amongst the higher species, which are confluent with 

 Helvella, and, secondly, amongst the lower species, which are 

 confluent through Helotium, a sub-genus of Peziza, with 

 Vibrissea (Fig. 66, d). 



302, A few of the Pezizce not only loose entirely their cup- 

 like form, but become confluent at the margin, as P. confluens, 

 and thus produce a nearly uniform stratum, which is distin- 

 guishable from similar Hymenomycetes, as Corticium, only by 

 the fruit. This paves the way to the genus Psilopezia, which 

 is totally destitute of margin, and is, in fact, an ascigerous 

 Corticium, or to Rhizina, remarkable for its tufts of roots 

 and curious sporidia (Fig. 67, b). A far more degenerate form 

 of Ascomycetes occurs on leaves, causing them to swell and 

 blister, as in the peach, walnut, and pear, consisting of little 

 more than asci, accompanied by very short moniliform 

 threads. This is the genus Ascomyces, one of the most obscure 

 amongst Fungi, but from its structure and effect on vegetation 

 not devoid of interest (Fig. 66, c). 



803. Tulasne* has sho'wn that there is a second form of fruit 

 in some genera, as, for example, in Bulgaria, of the present 

 division; Cenanfjium, Tympanis, and Dermatea, of the fore- 

 going. -f- These bodies are variously situated and shaped, and 



* Auu. d. Sc. Nat., s6r. 3, v. 20, p. 129. 



t In Cyttaria Darwinii, Berk., there are little black specks on ilio 

 base, Avhich will probably prove pyenidia or spermatogonia. 

 19 * 



