CHAPTER V. — COMPARATIVE REVIEW. — BASIDIOMVCETES. 329 



host, and a mycelium which spreads widely in the part of the plant which it attacks, 

 deforming it more or less, and producing the basidial layer directly from its hyphae. 

 The basidia are as usual club-shaped, and abjoint four fusiform spores. The spores 

 divide as soon as they are ripe by transverse walls into four cells, and the two end- 

 cells germinate at the expense of the protoplasm of the other two as soon as they 

 reach a moist surface. If this is the surface of a young foliage-leaf of Vaccinium, 

 the germination consists in the putting out of a tube, which at once grows through 

 the young epidermis into the inner tissue of the leaf and there developes a mycelium. 

 The mycelium forms the hymenium which bears the basidia directly; the time 

 required in plants cultivated artificially is about 14 days from the sowing of the spores. 

 If the spores germinate on some other substratum not so favourable as the leaf of 

 Vaccinium, the germ-tube after attaining a short length begins to sprout and pro- 

 duces rather elongated fusiform sprout-cells which sprout only at their extremities. 

 The formation of sprouts may be repeated many times. Brefeld saw it continue for 

 a year in specimens cultivated in nutrient solutions, and the power of production 

 appeared to be unlimited. It can scarcely be doubted that the sprout-cells can give 

 rise to a mycelium like that of the primary spores in suitable substratum ; but this has 

 never been actually ascertained. 



The development of the Tremellineae, the species of Dacryomyces for example 

 especially, would appear from the investigations which have been made to be the same 

 as in Exobasidium. I refer partly to the statements of Brefeld 1 , partly to an 

 unpublished series of researches conducted by Klebs. A mycelium is developed from 

 the germinating basidiospore under suitable conditions of nutrition, and the branches 

 from the mycelium combine to form compound sporophores which produce new 

 basidia. Under different conditions, not in all cases exactly defined, the germ-tubes 

 which proceed from the spores remain short and abjoint (successively ?) small secondary 

 spores or develope by sprouting. We shall return to these phenomena in a subsequent 

 page. There is moreover a further point of agreement between Dacryomyces and 

 Exobasidium ; the ripe basidiospore at the time of abjunction divides by transverse 

 walls into short disc-like cells, daughter-spores, which are usually four in number, 

 but each of these is capable of germination in Dacryomyces in one of the forms 

 stated above. In other Tremellineae the basidiospores do not divide or they divide 

 in a different and peculiar form. 



We are acquainted with the whole of the life-history of the Hymenomycetes 

 proper in Typhula and species of Coprinus through the researches of Brefeld ; in 

 Agaricus melleus through those of R. Hartig and Brefeld ; in Crucibulum and Cyathus, 

 genera of the Nidularieae, from the labours of Eidam and Brefeld, and in Sphaerobolus 

 from those of E. Fischer. 



The germinating spore of Agaricus melleus and Coprinus stercorarius puts 

 out a germ-tube, which in all the Coprini is swollen into a vesicle at its point of origin ; 

 the germ-tube developes directly into a mycelium and the compound sporophores are 

 formed directly on the mycelium from the ramifications of the hyphae. No organs 

 beside those described in the preceding pages, which can even be supposed to have 

 any connection with the propagation of the plant, nor any rudiments of them, have 



1 Hefepilze, p. 198. 



