222 Misccllaneom. 



peculiar organ of the Uredines, and that its frequency amongst their 

 sori or fertile groups, its relations of position, and its early appear- 

 ance authorise us in comparing it with the spermogonia of other 

 Fungi, so that the sexuality of the Uredines was not less probable 

 than that of the other families of the same order. 



Fresh investigations have shown me that the germ-filaments of the 

 spores do not all continue in the state of simplicity and continuity in 

 which I formerly saw them, and that perhaps they may constitute 

 the rudiments of the mycelium. 



Thus having sown perfectly ripe spores of JEcidium Euphorbice 

 sylvestris, DeC., their germ-filaments became less elongated than in 

 my previous experiments, made at a different time of the year, and 

 instead of remaining continuous, they divided by means of transverse 

 septa into four or six cells of unequal size ; then these cells, and espe- 

 cially the superior ones, each produced a short lateral appendage {spi- 

 cule), which soon bore an obovate and sUghtly oblique utricle. These 

 utricles were the last vegetative effort of these spores ; they became 

 free and then continue a separate existence, which was indicated by 

 the production of very slender filaments. After the isolation of these 

 bodies, the spore and the tube from which they were formed become 

 exhausted and destroyed, so that this tube or filament represents a 

 sort oi promycelium, an intermediate vegetation between the primary 

 spore and the utricles, which are either secondary spores, or perhaps 

 the only true spores, and the real producers of the true mycelium. 



The same facts may be observed in the Pucciiiice, the bilocular 

 fruits of which can commence vegetation without quitting the plant 

 which has supported them. In Puccinia graminis, Pers., I have seen 

 the tubes arising from these fruits acquire two or three times their 

 length, divide into cells hke the germ-filaments of the preceding 

 JEcidium, and hke these give rise lastly to nearly reniform spores 

 which soon germinated. 



The vegetation of the fruit of Phragmidium incrassatum. Link., 

 does not differ from that of the Pucciniee. The spores produced are 

 more globular than those of the above-mentioned Fungi. 



The Podisomata {P . juniperi communis, Fr., and P. /««cm»2. Cord.) 

 are Uredines by their parasitic existence and their mode of fructifi- 

 cation, whilst in their general appearance and consistence they re- 

 semble the Tremellce. Their bilocular fruits {sporidia, auct.) can 

 emit as many as eight tubes from their middle ; these are crossed and 

 superposed two and two, clothe the Fungus as with a sort of velvet, 

 and each produce several obovate spores, an immense abundance of 

 which may be collected as readily as of those of the Agarici or Tre- 

 mellce. 



In several Uredines which I have studied, such as Uredo Rosce, 

 Pers., U. suaveolens, Pers., Mcidium Tussilaginis, Pers., ^. crassum, 

 Pers., and some others, the tubular filaments which arise from the 

 fruits are capable of more or less ramification, so as to resemble the 

 true mycelium of Fungi still more closely. 



As regards the spermogonia of the Uredines, I will add that they 

 are organs the structure of which varies extremely little. They all 



