354 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



it is simply spread out over the matrix, swelling into a rounded 

 body, grooved so as to form an appearance like that of the 

 brain of some animal, or, finally, variously plicate or folded, so 

 as to present a large sporiferous surface. In Exidia the under 

 surface is distinct from the upper, and generally clothed with 

 short hairs or processes, which are sometimes very abundant, 

 so that it is tomentose, velvety, or sometimes almost strigose ; 

 and in Dacrymyces there is occasionally, but not always, a sort 

 of stem, as is also the case sometimes in Coryne. The most 

 curious part about the TremelUni is the fruit which has 

 only been lately explained. When I published my memoir 

 on the hymenium, I was content to notice the fact of the sin- 

 gularity of its structure, but I did not venture to publish my 

 sketch, as I did not fully understand the matter; now, however, 

 it appears clear from the observations of Tulasne, which have 

 been confirmed by many observers, that the hymenial surface 

 gives rise to globose bodies, answering to the sporophores of the 

 higher species. These, however, are sometimes more definite 

 than sporophores are usually, exhibiting a concentration of 

 colour and even septa, and sometimes divided into several lobes, 

 generally four. After a time they give rise to a definite or 

 indefinite number of elongated flexuous threads, which bear 

 at their tips cymbiform spores. In some cases, these spores 

 produce little bodies from their sides, the nature of which is 

 not at present well ascertained (Fig. 77, b, c, d). 



383. The similarity between Tremella and Podisoma 

 (Fig. 6, a) was recognised years since, but it is only of late 

 that their relation is found to be one of homology. The so- 

 called spores of Podisoma are, to a great extent, identical with 

 the sporophores of Tremella. The structure of Podisoma is, 

 however, so exactly that of Puccinia, with the exception of the 

 gelatinous element, that it can by no means be removed from 

 the neighbourhood of the epiphytous fungi ; and its habitat on 

 living branches, on which it is to a great extent perennial, 

 confirms the correctness of such association. The confluence 

 of Hymenomycetes with Goniomycetes at these points is 

 extremely interesting. It has been doubted whether some 

 species of Tremella may not be mere states of other fungi, as. 



