32 



insufficient and incomplete if, as experience showed, smutted plants could grow from sterilized 

 grain. The different statements concerning new methods of sterilization and their effectiveness 

 are the natural results called forth by this erroneous course of thought. If the study of the 

 phenomenon had not thus been carried on from one point of view alone, the question would 

 have been considered from the opposite one ; that is, whether we had learned enough of the 

 way in which infection through smut fungi takes place, or whether the assumption, that infec- 

 tion is limited only to germinating seedlings, is far reaching enough. 



Until most recently, investigations of smut infection were carried on with the assumption 

 that infection takes place only in young germinating seedlings. The percentage obtained in 

 different experiments on smutted plants may be traced back to the previous blossom infection. 

 The germs of infection were already present in the seed which was thought to have been 

 infected by the sprinkling on of spores, as, for example, in the experiments made by Otto Rose 

 in Rostock, on which he reported in his inaugural address, Rostock, 1903, "Der Flugbrand der 

 Sommergetreidesaaten und Massnahmen zur Bekampfung dieses Pilzes in der landwirthschaft- 

 lichen Praxis" (Loose smut of the seed of summer grains and regulations for fighting this 

 fungus in agriculture). We repeated the experiments with different varieties which in Rose's 

 experiments had given the highest and lowest percentages of smutted heads. The seed material 

 obtained from the same source was partly sprinkled with spores, partly disinfected, and sown 

 the end of March in the open field. As is evident from the following table of experiments 

 made with different varieties of barley, the results were the same in both cases. The average 

 temperature in the first three weeks after sowing was somewhat lower than in Rose's early 

 sowing. Our later work will throw light on the question of the conditions causing the different 

 results in Rose's early sowing, and in his late one. 



Percentage of smutted stalks in 

 Barley varieties. Sterilized Seed Seed mixed with Smut 



1. Bestehorn's 0.5 0.5 



2. Bestehorn's Kaiser o o 



3. Chevalier 3 3 



6. Golden Drop o o 



5. Greek, six rowed o o 



7. Hanna o 0.5 



8. Imperial, loose o o 



9. Imperial, irregularly arranged 2 o 



12. Mandschurei o o 



II. Moravian i J 



13. Naked, small blue o o 



14. Naked, large, 2 rowed o o 



16. Naked, 3 forked Neapolitan o o 



17. Oderbrucher 0.5 0.5 



19. Probsteiner o o 



18. Phoenix v. Thillau o o 



