On the genetic Connection between Peridermium 



giganteum (Mayr) Tubeuf 1} and Cronartium 



quercuum (Cooke) Miyabe. 



By 

 M. Shirai. 



With PL 1V-V. 



Since the discoveries of the genetic connection between Coleosporium 

 senecionis and Peridermium oblongisporium by K. Wolff in 1876, and 

 of that between Cronartium asclepiadeum and Peridermium Comui by 

 Cornn in 1886, eminent observers such as Hartig, Eostrup, Von Thtimen, 

 Plowlight, Klebahn, Fischer and others have repeatedly studied these rela- 

 tions as well as the connections between other winter-spore generations of 

 these two genera and their peridermium fructifications; and it is from the 

 effort of these workers that several perfect species of these heterocious fungi 

 have been established. 



Here in Japan, we find at least two different forms of Peridermium 

 attacking pines, (Pimcs densiflora, P. Thunbergii, P. parviflora and P. 

 liuchuensis.) one on the leaf and the other in the bark. 



The exact name of the leaf-infecting species is not yet determined, 

 while that found on the bark was first examined by H. Mayr during 

 his stay in Tokyo, and was named by him Aecidium or Peridermium 

 giganteum P 



A Cronartium is also found on the leaves of some deciduous species 

 of Quercus, such as Quercus serrata, Q. variabilis, Q, glandulifera, etc. 



This species has been identified by K. Miyabe of Sapporo with 

 Cronartium asclepiadeum (Willd) Fr. var. quercuum Cooke, which he 

 proposes to call Cronartium quercuum. 



1) F. Tubeuf, Pflanzenkrankheiten. Page. 429. 



2) H. Mayr, TJber die Kieferri des japanischen Eeihes- Bot. Centralbl. 1894. Bd. 



LVIII. Page 149. 



