THE FUNGI WHICH CAUSE PLANT DISEASE 361 



and August, usually hypophyllous, and the sori are very small 

 and inconspicuous. 



Artificial infection of Rubus with the spores of the Caeoma stage 

 by Tranzschel ^'^ gave rise to the telial form, demonstrating 

 the identity of the two. Cultures were also made by Clinton 

 about the same time. 



Xenodochus Schlecht (p. 355) 



^ciospores catenulate; uredinia wanting; teliospores short- 

 pedicelled, several celled in linear arrangement. 

 X. carbonarium Schl., autcEcious on Sanguisorba in Europe. 



Kuehneola Magnus (p. 355) 



jGcia wanting; uredinia piolvuiate, teha similar to Phragmidium 

 but with smooth spores with the germ pores apical. 

 K. uredinis (Lk.) Arth. 



II. (=Uredo muelleri.) Uredinia lemon-yellow, minute dots; 

 spores globose to elliptic, about 26 /x, hyaline, slightly verrucose. 



III. Telia solitary, pale, 250-500 /i broad; spores 5 to 6 to 

 12-celled, epispore hyaline, cells 17-47 x 15-26 fi; basidiospores 

 8.5-9.5 M- 



The telia are pale yellowish-white, thus readily distinguishing 

 t'.iem from other Rubus rusts. 



The lu-edinia are common and sometimes injurioiis on Rubus. 

 The sori are small and scattered. 



K. gossypii (Lagerh.) Arth. is reported on cotton in British 

 Guiana,^ also Florida, Cuba and Porto Rico. 



Gynmosporangium Hedwig f.=»6-"i- ^la- -" (p. 355) 



Cycle of development including pycnia, aecia and telia, with 

 distinct alternating phases; heteroecious and autcecious. Pycnia 

 and other sori subepidermal. 



0. Pycnia deep-seated, usually globoid, generally prominent 

 and conspicuous, at first honey yellow, usually becoming blackish, 

 globose or flattened-globose, with ostiolar filaments. 



I ( =Roestelia) erumpent, at first cylindric. Peridium dingy 

 white, usually elongated into a tubular form, membranous, tending 



