38 



FUNGI. 



as species of LecytJiea. In Cystopus, the spores are sub-globose, 

 or somewhat angular, generated in a moniliform manner, and 

 afterwards separating at the joints. The upper spore is always 

 the oldest, continuous production of spores going on for some 

 time at the base of the chain. Under favourable 

 conditions of moisture, each of these spores, or 

 conidia, as De Bary terms them, is capable of 

 producing within itself a number of zoospores; * 

 these ultimately burst the vesicle, move about by 

 the aid of vibratile cilia, and at last settle down 

 to germinate. Besides these, other reproductive 

 bodies are generated upon the mycelium, within 

 the tissues of the plant, in the form of globose 

 oogonia, or resting spores, which, when mature, 

 also enclose great numbers of zoospores. Similar 

 oogonia are produced amongst the Mucedines in 

 the genus Peronospora, to which De Bary con- 

 siders Cystopus to be closely allied. At all events, 

 FIG. 19. Cystopus this is a peculiarity of structure and development 

 not as yet met with in any other of the Cceomacei. 

 In TJromyces is the nearest approach to the Puccinicei ; in fact, 

 it is Puccinia reduced to a single cell. The form of spore is 

 usually more angular and irregular than in Trichobasis, and the 

 pedicel is permanent. It may be remarked here, that of the 

 foregoing genera, many of the species are not autonomous that 

 have hitherto been included amongst them. This is especially 

 true of Lecythea, Trichobasis ^ and, as it now appears, of 

 Uromyces.^ 



PUCCINLEI. This group differs from the foregoing chiefly in 

 having septate spores. The pustules, or sori, break through 

 the cuticle in a similar manner, and here also no true peridium 

 is present. In JCenodochus, the highest development of joints 

 is reached, each spore being composed of an indefinite number, 

 from ten to twenty cells. With it is associated an unicellular 



* De Bary, "Champignons Parasites," in "Ann. des Sci. Nat." 4 me ser. vol. xx. 

 t Tulasne, "MemoiresurlesUredine'es, &c.," in" Ann. des Sci. Nat." (1854), 

 vol. ii. p. 78. 



