UREDINALES 569 



tion and plasmogamy takes place, as may occasionally happen in Puccinia 

 malvacearum (Lindfors, 1924), at the base of the hyphal knot between two 

 neighboring hyphal cells (Mme. Moreau, 1914) or even before the forma- 

 tion of the telia, between two ordinary mycelial cells (Blackman and 

 Fraser, 1906). 



In a fourth group, e.g., Uromyces Scillarum (Blackman and Fraser, 

 1906; Mme. Moreau, 1914), Puccinia Adoxae (Blackman and Fraser, 

 1906) and P. Aegopodii (Kursanov, 1922), plasmogamy takes place 

 between two vegetative cells long before the formation of the telia. 



In the fifth group, finally, to which belongs Uromyces Rudbeckiae 

 (Olive, 1911), plasmogamy is entirely lacking and the life cycle is apomic- 

 tic in the uninucleate phase, as in Endophyllum Euphorbiae-silvaticae and 

 some strains of Caeoma nitens. 



As teliospores of all five forms of fructification in the Uredinales have 

 undergone very great differentiation in form and appearance, they offer 

 very important characters for systematic groupings within the order. 

 In them are four types which correspond to the families: Coleosporiaceae, 

 Melampsoraceae, Cronartiaceae and Pucciniaceae. 



Coleosporiaceae. — In the Javan Goplana mirabilis on leaves of 

 Meliosma, the sorus is extramatrical on the underside of the leaf, where it 



Pig. 382.- — 1. Goplana mirabilis. Hymenium. 2. Uredinopsis filicina. Zeugite, z, in 

 spongy mesophyll. (1 X 320; 2 X 410; after Sydow, 1915, and E. Fischer, 1904.) 



looks macroscopically like a simple species of Septobasidium. The 

 terminal cells of the extramatrical mycelium change as in the latter to a 

 basidium; the subterminal cells develep laterally, as in Iola, to new basidia 

 so that finally every hypha bears a small cluster of basidia (Fig. 382, 1). 

 The peripheral cells of the sorus remain sterile and are transformed into 

 periphyses. 



In Coleosporium Sonchi-arvensis (Sapin-Trouffy, 1896), C. Solidaginis 

 (Holden and Harper 1902) and C. Campanulae (Juel, 1898), the 

 binucleate, intercellular hyphae grow out of the interior of the host 

 tissue toward the epidermis and come together beneath it to form 

 a palisade layer (Fig. 383, 1). The terminal cell of each hypha 



