3 86 FUNGI 



derm, and giving rise within to the mycele which ultimately bears the 

 sporocarps and antherids. 



Gymnosporangium (DC.) represents another type of the course of 

 development in Uredineae. The sporocarps (corresponding to aecidia, 

 but here denoted by the form-genus Roestelia, Reb.) appear in summer 

 on the leaves and fruits of Pomeae. No uredospores are formed. 

 The next generation (teleutospores) is produced in spring on juniper in 

 odd-shaped mucilaginous brown or yellow masses. Promyceles are formed 

 which bear sporids, and these again set up on the leaves, &c., of Pomese 

 the sporocarp generation. 



A farther reduced type is to be found in Endophyllum (Lev.). In 

 this case the germ-tube of the spores of the sporocarp (aecidiospores) 

 becomes a promycele, and, dividing up into several cells, each of these 

 bears at the end of a sterigma a single sporid. The sporid on germi- 

 nating renews the sporocarp generation. 



Two cases of exceptional structure may be noted. In Phragmidium 

 (Link) the sporocarps have no proper envelope, the place of the wall 

 being taken by a circle of club-shaped paraphyses surrounding the 

 margin of the hymenia. On the other hand the uredospores of Me- 

 lainpsora populina (Jacq.) and of Cronartium (Pers.) are enclosed in 

 an envelope resembling that of the sporocarp. The development of 

 the paraphyses in the one case and of the envelope in the other requires 

 investigation. 



Besides the sporocarp-forming Uredineae there is another group 

 known as the tremelloid Uredinece, which do not possess a sporocarp 

 generation. These are not to be confounded with those Uredineae in 

 which presumably from want of investigation the sporocarps are un- 

 known. The course of development of the tremelloid Uredineae is per- 

 fectly well known in a number of cases (Leptopuccinieae and Leptochry- 

 somyxa, de By.), and consists of a teleutospore-bearing generation with 

 commonly softer and more gelatinous spore-membranes. These teleuto- 

 spores germinate as a rule at maturity and not after a period of rest. 

 The sporids formed on the promycele produce a mycele which again 

 bears teleutospores. Leptopuccinia malvacearum (Schroet), L. Dianthi 

 (Schroet), &c., bear the same relation in appearance, &c., to Puccinia 

 as Leptochrysomyxa Abietis (Ung.) bears to Chrysomyxa (Ung.), the 

 species of which form sporocarps, uredospores, and teleutospores. 



Enough has been said in this brief account to indicate a probable 

 connection of the Uredineae with the Ascomycetes through their 

 sporocarps. Those .forms the tremelloid Uredineae in which the 

 sporocarp generation may be presumed to have been lost, sufficiently 

 resemble the complete types to be necessarily bound up with them ; 



