Miscellaneous. 77 



priori extremely improbable. Direct observation does not appear to 

 me to render it at all more probable, for the productions in question 

 are often met witb quite independently of each other. As to those who 

 only see in the Uredines and their hosts, associations or cohabitations 

 comparable to those of the various grasses which compose our mea- 

 dows, they perhaps will not recognize the importance of the pheno- 

 menon in question, and may misunderstand its signification. Against 

 them they have the often striking resemblance between the Uredo 

 and the Fungus which is united with it, and especially the constant 

 order of their respective appearance, the Uredo always preceding its 

 companion. This resemblance and succession evidently indicate re- 

 lations between the productions which present them, and as these 

 relations cannot be those of parasitism, they may be with more pro- 

 bability regarded as the indications of specific identities, which were 

 suspected by some old observers, but which have been universally 

 neglected by the mycologists of the present day. In truth, there is 

 scarcely room to hope that we shall ever be able to furnish a direct 

 proof of this identity, or one obtained by sowing, in consequence of 

 the almost insurmountable difficulties attending the culture of Fungi, 

 and especially that of the Entophyta ; but even if the supposed proof 

 were obtained in this maimer, it would still be very legitimately open 

 to criticism from the nature of these difficulties, and moreover its 

 place may readily be supplied. At least, I think, that the attentive 

 observation of the successive development of the heterosporous Ure- 

 dinece gives us sufficient authority for believing that these are not, as 

 is now generally supposed, Uredines associated in pairs, but Uredines 

 furnished with a double apparatus of reproduction and capable in 

 consequence of assuming two different forms. 



Amongst these peculiar Uredinece, the Phragmidia and Puccinice 

 are those which have especially attracted the attention of observers. 

 Many have thought that the spherical or oval spores which are first 

 produced in their sori, and which now constitute various species of 

 Uredinece (Lecythece s. Epitece and Trichobasis sp. recentior), were 

 only either the true grains of these Phragmidia and Puccinice, or a 

 still imperfect state of their plurilocular fruit. The former of these 

 opinions wrongly supposes that these pretended grains are engendered 

 in these backward fruits, and the second requires the admission of 

 a transformation which has not actually been proved ; but both 

 ascribe to one and the same plant the two sorts of reproductive 

 bodies which succeed each other on the same pulvinulus (Chirode, 

 Lev.). In a great number of Puccinice, fruits intermediate in form 

 between the spherical grains or Uredo, and the bilocular fruits or 

 Puccinia, indicate evidently that these two kinds of reproductive 

 organs belong to one and the same Fungus. Nevertheless, notwith- 

 standing the numerous examples of dimorphism presented by the 

 Phragmidia, Puccinice and Uromyces, these Uredinece do not per- 

 haps prove our opinion in so satisfactory a manner as the Cofeosporia, 

 Melampsorce and Cronartia. 



The pulvinuli of the Coleosporia, Lev. {Uredo tremellosa, Str. et 

 affines) have at first apparently all the same organization ; but some 

 of them soon become converted into spherical and pulverulent fruits 



