i/HhWlNEu^. 



315 



Fig. 219.— Yonnz teleute- 

 sporcB of Phraginidium m/Ur- 

 cvonatum, showing tlie an- 

 gular maeees which eventu- 

 ally develop into the cells 



ture follow or proceed from a sexual act ; and maintains that the secid- 

 ium fruit is more complex in structure than any of llie oiliers. He 

 further says, " The Eecidium fruit corresponds, then, to the perithecium of 

 the Ascomycetes, tlie secidiospores to the ascospores ; and the uredo- 

 spores and teleutospores are evidently differ- 

 ent forms of conidia." It is very doubtful, 

 however, whether future investigations will 

 prove the correctness of Sachs' surmise. It is 

 much more probable that the teleutospores re- 

 sult from a sexual act, and that they are to 

 be compared to the asci of the Ascomycetes. 

 The teleutospores are possibly reduced asci, 

 containing one or more large ascospores ; in 

 some cases— e.g'., in Puccinia Helianthi — an 

 outer investing membrane can be distinguisli- 

 ed after treatment ■vvith potassic hydrate, 



while in Puccinia ( Uropyxis) Amorphm there of 'the mature teleutospore. 

 is " a deciduous outer coat,"* which contains ° y^^S"" ^ • 

 the double spore, and (when moistened) a mass of jelly. In both these 

 cases the membranous covering closely resembles an ascus which fits 

 closely over its contained double spore. In the genus Phragmidium 

 (Fig. 220), especially in young teleutospores, the resemblance to asci 

 and ascospores is still more striking ; the so- 

 called " cells" of the teleutospore originate as so 

 many separate masses in the interior of a large 

 ascus-like membrane (Fig 219) ; in their further 

 development the cells become large, and at last 

 fill up the whole cavity, and then have the ap- 

 pearance of Fig. 330. 



Tlie resemblance of the teleutospores to re- 

 duced asci is close enough to make it probable 

 that sexual organs resembling those of Asco- 

 mycetes will be found to precede them. This 

 is rendered the more probable from the resem 

 blance of eecidiospores, spermatia, and uredo- 

 spores to the conidia, spermatia, and stylospores 

 of var'ous Ascomycetous fungi, f 



(d) The principal genera in this order are 

 Uromyces and Melavnpsora with one-celled te- 

 leutospores, Puccinia and Qymnonporangium, 

 with two cells, and Phragmidium (Fig. 220) with 

 many cells. Many species are known, there being in the genus Pw) 



Fig. 220 —Mature teleu- 

 toepores of Phragaiidmm 

 buUtosum. Highly magnl- 

 fled.— After Cooke. 



* So described by Berkeley : " Introduction to Cryptogamic Botany, " 

 1857, p. 325. 



\ Some of these resemblances were pointed out many years {igo by 



