248 INTRODUCTION TO THE STUDY OF FUNGI 



branched, whilst the proiuycelium is tiiseptate. In three small 

 genera the teleutospores are longitudinally septate ; that is, in 

 Pucciniastruvi, in which the uredospores are enclosed in a pseudo- 

 peridium, but the teleutospores are evolved externally to the 

 matrix ; Thecopsora, in which the uredospores are also enclosed 

 in a pseudoperidium, and tlie teleutospores are intracellular ; in 

 Calyptos2')ora there are aecidia but no iu"edospores, and teleuto- 

 spores, provided it is accurately determined that, in the single 

 species, the aecidium is found on the leaves of Abies, and the 

 teleutospores on the branches of Vaceinium. In the remaining 

 two genera the teleutospores are enclosed in a pseudoperidium — 

 in Endopliyllum resembling an Aecidium with catenulate spores; 

 and in Milesia the teleutospores are catenulate within a reticu- 

 late immersed pseudoperidium. These two genera are outsiders 

 and only remain here on sufferance. 



TheDictyosporae, in which the teleutospores are transversely, 

 longitudinally, and obliquely septate, contain but two very 

 distinct but different genera. In Triphragmium the teleuto- 

 spores are triseptate, or radiately three-celled. In JRavenelia 

 the teleutospores are many-celled, the cells radiating or con- 

 centric, often with hyaline basal cells, in surface aspect re- 

 sembling the glomerules of Sorosporium. 



In such an arrangement as the foregoing, wherein so much 

 depends upon a knowledge of the life-history of every species, 

 it is but natural to expect that there will be a number of forms 

 which present the earlier stages of a succession, and are yet 

 deficient of the requisite determinator, the teleutospore. These 

 have to be relegated to outside groups under the denomination 

 of Inferior Uredines, or Imperfect Uredines, and as such find 

 their places under the following genera. The species having 

 spermogonia only are ranged under Aecidiolum — the species of 

 Aecidium, which remain isolated, retain their position under 

 that old generic name ; the species which are analogous, but 

 have elongated pseudoperidia, and were formerly known as 

 Baestelia, still retain that name, producing aecidiospores, as also 

 does Peridermium, which is analogous to Aecidium, on conifers. 

 The remaining genus is Uredo, which includes aU unplaced 

 species of uredosporous Uredines, whether known formerly as 

 Uredo, or Trichohasis, Lecythea, or Caeoma, the latter having the 



