F UNO I. R A SIDIOMYCE TES. j ., ," 



celled teleutospores (///, /), and soon the formation of uredospores ceases altogether ; 

 teleutospores only are henceforth produced (77), and with this the period of vegetation 

 closes. The teleutospores remain in a resting state on the grass-stems during the 

 winter and germinate in the spring ; then they send out of their two cells short septate 

 germ-tubes, the promycelia (Fig. 86, A, ), the terminal cells of which at once produce 

 sporidia on slender branches. But these sporidia only develope a new mycelium when 

 they germinate on a leaf of Berbcris, and their germination is different from that of other 

 forms of spores, because the tube, like that of the Peronosporeae, pierces the epidermal 

 cell (C, sp and z) and passes through it and into the parenchyma ; there it developes a 

 mycelium which causes the swelling of the leaf with which we set out, and then produces 

 aecidia and spermogonia. 



The genus Gymnosporangium has no uredospores ; its aecidia, which are known 

 by the name of Roestelia, appear in July and August on the leaves, leaf-stalks, and 

 fruits of the Pomaceae (Pyrus, Cydonia, Sorbzts), and have the shape of long-necked 

 flasks, which open by slits at the top or at the side and are sometimes as much as eight 

 millimetres in length. The chains of spores have a peculiarity, not however entirely 

 confined to them ; a sterile cell, which subsequently disappears, lies between every two 

 fertile cells. The masses of teleutospores in Roestelia {Gymnosporangium) appear 

 in spring before the aecidia on species oijuniperits in the form of lumps of mucilage 

 which may be round, conical, club-shaped, tongue-shaped, pectinate or palmate, and 

 yellow or brown in colour ; these contain closely crowded basidia, which spring from 

 the mycelium beneath the epidermis of the leaves and in the cortical tissue of the 

 branches and produce the teleutospores. The teleutospores resemble those of Ae. 

 Berberidis, and like them produce promycelia, the sporidia from which develope into 

 Roestelia with aecidia on the leaves of the Pomaceae. 



6. THE BAS1DIOMYCETES 1 . 



To this division belong the largest and handsomest Fungi, the fructifications of 

 which, the well-known ' mushrooms,' produce gonidia. The early stages in the 

 life-history of these fructifications, before imperfectly known, are now cleared up 

 by the researches of Brefeld. The peculiar feature in these plants is that no sexually- 

 produced fructification, corresponding to the ascus-fructification of the Ascomycetes, 

 is to be found, or at least has yet been found, at any stage in the course of their 

 development ; for the massive structures of closely-interwoven hyphal tissue, on which 

 the basidiospores are formed, are not comparable with the fructifications of the 

 Ascomycetes, but are simply large gonidiophores (carpophores). The spores, which 

 are known as basidiospores, germinate, and produce a mycelium, on which new go- 

 nidiophores (the stalked pileus in one section of the Basidiomycetes) are formed by 

 the branching and interweaving of hyphae either directly, or indirectly after inter- 

 calation of a sclerotium. Besides these large gonidiophores the mycelia of many 

 genera also bear gonidiophores, termed by Brefeld ' Stabchenfructificationen ' (rod- 

 fructifications) ; these consist of short branches of the mycelium from which small 

 gonidia-like rods ('stabchen') are abscised, but which have lost the power of germi- 

 nation except in the lowest group of the Basidiomycetes, namely the Tremellineae. 



Though there is more than usual variety in the outward form and interior struc- 

 ture of the fructifications of the Basidiomycetes, yet the formation of the spores 

 themselves follows a common type ; certain branches of the fertile hyphae swell into 



1 De Bary, Morphol. u. Physiol. der Pilze, Leipzig 1866, [and Vergl. Morph. u. Biol. d. Pilze, 

 1884]. Brefeld, Untersuch. li. d. Schimmelpilze, III. Heft. 



K 2 



