264 CURREY, ON THE REPRODUCTIVE 



Thei"e are many Fungi in which bodies analogous to the 

 speraiogonia and spermatia of Lichens are found to exist, and 

 as far as presc^nt observation has extended, these bodies are 

 found to precede the formation of the perfect spores. The 

 genus j^cidium is very favourable for an examination of these 

 organs. Tlie spermogonia occur in spring upon those parts 

 of the plants upon which perfect ^cidia are afterwards 

 found ; they are in the form of minute punctiform specks, 

 covering the pale or red spots upon which the j^cidia are at 

 a later period produced. A microscopical examination of 

 these specks shows them to be globular bodies, open at the 

 top, having their walls composed of densely-interwoven 

 threads originating from the mycelium, and containing in 

 their interior other threads converging towards the centre of 

 tlie spermogonium, and bearing spermatia at their apices. 

 The spermatia are produced in great abundance, and form a 

 granular mass, filling the hollow of the spermogonium. The 

 upper threads of the walls (namely, those which are situated 

 next to the apicular opening of the spermogonium) are some- 

 what more upright than the others, and are directed towards 

 the epidermis of the surface of the leaf; and by the growth 

 of these upper threads and the increase of the granular mass 

 of spermatia, the spermogonium increases in size, raises, and 

 eventually breaks through the epidermis, the outermost 

 threads forming a small red funnel-shaped tuft, through 

 which the spermatia eventually escape, and are dispersed 

 around the spermogonium. After the ripening of the sper- 

 mogonia, the perithecia of the true yEcidia are formed on the 

 same mycelium, and the spermogonia then decay. 



Spermogonia, such as those just described, are not confined 

 to the genus j^cidiain ; tliey are common to other genera in 

 the tribe of the Uredineo', occ urring in Cceoma, Hcsstelia, 

 Peridermium, Pliracjmidium, Trijdiragmium, and Pucchda. 

 In Cystojius, Melantpsura, Culeosporium, and Uromyces, they 

 have not as yet been ascertained to exist. Nor are spermo- 

 gonia peculiar to the tribe of the Uredineoe ; they occur M'ith 

 certain, but not essential differences of structure, in many 

 other Fungi. It has been shown by the observations of Fries, 

 Tulasne, and other my;ologists, that several sorts of Fungi, 

 long supposed to form distinct genera, are, in fact, only early 

 states of other well-known plants : thus the genera Septoria^ 

 Cytispora, Neniaspora, Header sonia, and others, are now con- 

 sidered to be the spermogonia of s})ecies of Sph(erice ; Melas- 

 mia is supposed to be the spermatiferous state of Rhytisma ; 

 Leptostroma probably of Hysterium, Phacidium, etc. . . . 

 In a paper published in the ' Annales des Sciences ' for 



