2 4 



Z. A variety of wheat from Grabschen which blossoms later was infected in the separate blossoms 

 on July 15, in three different places. Fresh smut was used, however, from the field of Schlanstedt wheat. 

 Young germinating seedlings from the sterilized grain were grown in March, 1904, on sterilized sand 

 from the river Oder, and transplanted on the 21st of April, to open ground. 



Seed bed 1 furnished 169 stalks, of which 68 per cent were smutted. 



" 2 " 168 60 



" 3 " 267 85 ' 



3. Just as in the first experiments, Schlanstedt wheat was infected in July, 1903, with smut spores 

 of the same kind in the separate blossoms and the sterilized grains were treated as above. 



Of 171 stalks thus grown, 61 per cent were smutted. 



4. Schlanstedt wheat was infected on July 16, 1903, with fresh smut spores from the field of land 

 wheat (Landweizen) from Grabschen, the harvested seed being treated as above. 



Of 160 stalks, 62 per cent were smutted. 



5. On July 23, 1903, blossoming heads of land wheat were infected in Grabschen with fresh smut 

 spores of the same variety, which were finely divided in very dilute malt. The liquid containing the 

 spores was introduced with a fine brush into the separate blossoms shortly before they opened. 



The harvested seed was sterilized, planted in March, 1904, on sterilized sand from the river Oder, 

 and transplanted April 21st to open ground. The infection was carried out in three different beds. 

 The seed from bed 1 developed 129 stalks, of which 81 per cent were smutted. 



2 " 204 96 " 



(Fig. 1, plate I, was taken from this lot.) 

 The seed from bed 3 developed 140 stalks, of which 78 per cent were smutted. 



6. Finally, Kostrom wheat was infected in its blossoms under the same conditions as the varities 

 above named. 



a. With smut spores from the same variety. 



of 175 successfully developed stalks 51 per cent were smutted. 



b. With smut spores from a field of Schlanstedt wheat; 



of 53 stalks, 63 per cent were smutted. 



c. With fresh smut spores from the same field which were sprayed on in malt; 



of 73 stalks, 38 per cent were smutted. 



In all these experiments, controls were grown from sterilized seed from the same fields. In all, either 

 no smut developed or an isolated smutted specimen occurred only once in a while. 



II. CYLINDER INFECTION. 



Wheat from Leerbeutel, just beginning to blossom, was infected in the cylinder, July 4, 1903, with 

 fresh smut spores from a wheat field in Grabschen. The seed was sterilized and in April, 1904, sown 

 directly in open ground. The infection was carried out in two different places. The seed harvested in 

 1904 was planted in two separate beds. 



In bed 1, of 442 stalks, 19 per cent were smutted. 

 " " 2, " 625 " 24 " 



A control of non-infected heads from the same field gave 0.4 per cent of smutted stalks. 



III. INFECTION OF THE YOUNG GERMINATING SEEDLINGS. 



1. Young germinating seedlings of a variety of wheat from Leerbeutel were sprayed with smut 

 spores of wheat from Miinster, which were just ready to germinate, and distributed in very dilute nutrient 

 solution. Half of the seeds grown in germinating cases were then planted on good, well-manured farm 

 soil, and the other half on not very fertile sandy soil. 



In the good soil, 0.3 per cent of 480 stalks were smutted. 

 In the poor soil, no smutted example was found In 360 stalks. 



2. Young germinating seedlings of Schlanstedt wheat were treated exactly as above described with 

 smut spores from Miinster and the seedlings transplanted to good and to poor soil. The same experi- 

 ments were repeated four times in the same way, from the middle of March to the end of April. 



In experiments 1 and 2, out of 400 stalks planted in good and in poor soil, none were smutted. 



In experiment 3, out of 240 stalks planted in good soil, none were smutted. 



In experiment 3, out of 200 stalks planted in poor soil, 1.4 per cent were smutted. 



In experiment 4, out of 250 stalks planted in good soil, none were smutted. 



In experiment 4, out of 220 stalks planted in poor soil, 2 per cent were smutted. 



