1919] 



MATSUMOTO — CULTURE EXPERIMENTS WITH MELAMPSORA 



313 



Nakajima Park, Sapporo, where there were growing many 

 species of Populus badly attacked by the Melampsora rusts. 

 These indications, in the light of results obtained by Klebahn 

 in Germany, induced me to assume that there might be some 

 relationship between the Caeoma on Chelidonium and the Mel- 

 ampsora on some species of Populus. However, in the inocula- 

 tion of Chelidonium with Melampsora from Populus (1915), no 

 light could be thrown on this subject; therefore in the following 

 year additional cultures were made, but these also failed to 

 yield any positive results. 



After these successive negative results, the w r riter made 

 cultures with species of Melampsora from Populus balsamifera 

 on Larix leptolepis, Larix decidua, Ribes grossularia, and Allium 

 Cepa. A study of the data in table n show r s that the sporidia of 

 the rust on Populus balsamifera infect Larix leptolepis and Larix 

 decidua without any apparent preference, while on the remaining 

 plants they prove to be quite ineffective. 



TABLE II 



SHOWING THE RESULTS OF INOCULATIONS WITH MELAMPSORA 



FROM POPULUS BALSAMIFERA 



Inoculation 

 material 



Species 

 inoculated 



Date of 

 inoculation 



Result 



Date of 

 first sori 



Teleutospores 

 from 

 Populus balsamifera 

 Populus balsamifera 

 Populus balsamifera 

 Populus balsamifera 



Larix leptolepis 



Larix decidua 

 Ribes grossularia 



Allium Cepa 



May 2 

 May 2 

 May 2 

 May 2 



+ 

 + 



May 18 

 May 19 



• • • • 



• # • • 



Caeomaspores 

 from 

 Larix decidua 



Populus 

 balsamifera 



M ay 24 



+ 



June 8 



The species can properly be regarded as Melampsora Larici- 

 populina Kleb. on account of the position of the uredo- and 

 teleutospore layer and the relationship between the different 

 spore forms and the host plants. The author observes some 



