340 DIVISION II. COURSE OF DEVELOPMENT OF FUNGI. 



are analogous cases known in the Ascomycetes which illustrate the opposite theory 

 of a retrogressive development. 



An attempt was made in former sections to show that the series of the Ascomy- 

 cetes connects with the Algae which form oospheres through the Peronosporeae 

 and Zygomycetes and their allies, and may be derived from them in progressive 

 succession ; also that the Uredineae are united as a member to this series. This view 

 may at present be said to be the one which accords best and most naturally with the 

 facts as known to us. But if this is the accepted view, we must necessarily adopt 

 that one of the alternative assumptions, which makes the tremelloid Uredineae and 

 Basidiomycetes degenerate descendants of those members of the series of the Ascomy- 

 cetes, to which observation directly points ; otherwise they must have a double phylo- 

 genetic origin, which can hardly be admitted in so comparatively narrow a group as 

 the Uredineae. The series of the Basidiomycetes when once parted off advanced to 

 a high and peculiar development, as is shown by the Amanitae, Phalloideae, Sphaero- 

 bolus, and other forms. 



The views which have been developed in the preceding paragraphs explain the 

 intimation given above on page 331 respecting the terminology of the reproductive 

 organs in the Basidiomycetes. The word gonidia has a different meaning here from 

 what it has in the series of Ascomycetes, where it was used with reference or in 

 opposition to the carpospores (page 129); in the Basidiomycetes, where there are 

 no carpospores, the term gonidia is applied to certain spores other than the basidio- 

 spores, and these are themselves phylogenetically homologous with certain gonidia of 

 the Uredineae. The question whether the gonidia of the Tremellineae can be 

 considered to be homologous with the uredogonidia of the Uredineae may fairly be 

 termed a needless one ; certainly there is little real objection to be made to this 

 view. Still the question necessarily connected with it, whether the ' rods ' observed 

 hitherto without germination in some Hymenomycetes (page 332) are homologous 

 with the gonidia of the Tremellineae, or are spermatia derived through the descent 

 from the Ascomycetes, had better be left for the present without an answer. Further 

 observations will perhaps determine these matters. 



The views here expressed respecting the genealogy of the Fungi are of course only 

 an attempt to bring the separate facts at present known into the unity of a single 

 scheme ; every displacement in the basis of facts may necessitate an alteration in 

 the scheme. 



The near connection which has been pointed out between the Hymenomycetes and 

 the Uredineae may well be regarded as an established fact that is not likely to be 

 set aside. There are certain alleged reasons why the former should be considered 

 to be derived phylogenetically from the latter, and not vice -versa. These are also 

 good reasons in the present state of our knowledge, but the progress of inquiry may 

 affect them, especially as they are derived, not only directly from the subject-matter 

 in question, but partly also from remoter sources. 



Starting from the same facts we may even now arrive at other results than these, 

 as appears from Brefeld's views 1 , though not without the help of some very bold 

 hypotheses. What is to be said concerning these views will be found in a former 

 treatise of my own 2 to which the reader is referred. 



1 Schimmelpilze, III and IV. 

 8 Beitr. IV, p. 131. 



