• on geraniacea: 105 



by a pore ; spores roundish-polygonal to oblong-ovate, densely 

 verruculose, yellow, 24 — 33 x 18 — 2(i jx. 



Uredospures. Sori hypophyllous, on yellow spots, in circi- 

 nate groups, seldom scattered, rather large, pulverulent, choco- 

 late-brown ; spores roundish, brown, distantly echinulate, 22— 

 26 fx ; epispore about 2 /x thick. 



Teleutospores. Sori hypophyllous, on yellowish or reddish 



Fig. 58. U. Kabatianus. Teleutospores and uredospore, on G. pyrenaicum. 



spots, rather large, covered with the thin silvery-shining epi- 

 dermis, generally in circinate groups, soon confluent, pulverulent, 

 brown ; spores ovate, often oblong, scarcely thickened above, 

 but with the germ-pore provided with a prominent subhyaline 

 papilla (up to 7 /x high), smooth, pale-brown, 22 — 42 x 13 — 20 /x\ 

 pedicels short, hyaline, deciduous. 



On Geranium pyrenaicum, and possibly on G. /nolle and 

 G. pusillnm. (Fig. 58.) 



This has been separated by Bubak from U. Geranii on the ground of 

 the circinate arrangement of the uredo- and telento-sori, and the more 

 oblong and longer teleutospores : the description of the ascidia and teleu- 

 tospores is taken from that of Bubak. According to Sydow, Lind has 

 succeeded in transferring this species from G. pyrenaicum to G. molle and 

 G. pusillum. Bubak thought that only this form occurred on G. 'pyrenai- 

 cum, but Bock (Centralbl. f. Bakt. 2, xx. 584) showed that typical 

 Uromyces Geranii could also be produced on that host. 



The two Uromyces are very closely allied, but several distinctions are 

 alleged : the uredospores themselves are identical, but not the sori ; 

 according to Sydow, the teleutospores of U. Kabatianus do not appear till 

 towards the end of October, are paler, longer and more oblong in shape 

 with a higher papilla, while their sori are generally circinate, paler and 

 less compact. The teleutospores of U. Geranii appear at the beginning of 

 summer, the sori are nearly black, rather compact, and more scattered. 

 I have specimens collected at Cambridge in August, on G. "pyrenaicum, 

 having the uredo-sori in circinate groups on conspicuous yellow spots, and 



