25 



IV. INFECTION OF THE SEED. 



The unsterilized seed was mixed, aa in earlier cases, with smut spores so that each grain was cov- 

 ered with a blaclt coating of them. The grains were sown directly on the open ground. 



1. From land wheat from Grabschen, infected with smut spores from the same field, 



280 stalks developed in good soil, of which 1 per cent were smutted. 

 160 " '• " poor " " " 2 " 



2. The same wheat treated as above with smut spores from a wheat field In MUnster, gave 



in good soil, 153 stalks, of which 0.7 per cent were smutted. 

 " poor " 200 0.5 " 



3. Schlanstedt wheat infected with smut spores from the same field, gave 



in good soil, out of 320 stalks, no smutted ones. 

 " poor " " " 350 " 2 " 



4. Kostrbm wheat infected with smut spores of wheat from Grabschen, as well as from the same 

 variety, gave 



in good soil, out of 200 stalks, no smutted ones. 

 " poor ' 150 " 1 " one. 



Controls from the same seed, from poor and from good soil, which had, however, been sterilized, 

 showed no smut in the cases of Schlanstedt and Kostrom wheat, either in good or poor soil. Wheat from 

 Grabschen gave 



in good soil, of 250 stalks, 2 per cent smutted ones. 

 " poor " " 100 " (they were all which developed) 4 per cent smutted ones. 



V. INFECTION OF THE SUBSTRATUM. 



1. Good compost was sown with the spores of the loose smut of wheat from Grabschen, on a sub- 

 stratum in the germinating cases. The seedlings were transplanted April 14, 1904, to open ground. 



From 200 maturefl stalks, 2 per cent were smutted. 



2. Kostrom and Schlanstedt wheat were treated in the same way and transplanted to open ground. 



(No smutted specimens whatever occurred for 200 stalks of each variety. 



3. The compost which had been infected with smut spores was mixed with fresh horse manure, 

 otherwise the experiments were carried out as under 1. They gave exactly the same results as under 1. 



C. INFECTION EXPERIMENTS IN 1905. 

 I. INFECTION OF THE SEPARATE BLOSSOMS. 



1. Blooming heads of a beardless winter w(heat were infected on June 16, 21 and 22, 1904, in the 

 separate blossoms with fresh smut from the same field. The infection was carried on in three different 

 places. The harvested and sterilized seed was sown in pleasant weather, in the autumn of the same year, 

 (on the 7th of October), directly on open ground. The seed harvested from the four different places 

 was planted in special beds. 



In bed 1, 256 stalks developed, of which 34 per cent were smutted. 



" 2, 267 " " " " 43 " 



" 3, 296 " " •• " 33 



" " 4, 230 " " " " 16 " " 



A control of 1,000 stalks of the same wheat had only one smutted specimen. 



2. The same wheat was infected with fresh wheat smut; the spores, however, were finely divided 

 in water and were put in the blossoms with a brush. From the seed, otherwise treated as under 1, in the 

 next year 



200 stalks developed, of which 14 per cent were smutted. 



3. The blossoms of bearded summer wheat were infected with fresh dry smut from the same field 

 in 1904 and the seedlings grown from sterilized seed on sterile sand were transplanted April 12, 1905, to 

 open ground. 



450 stalks developed, of which 63 per cent were smutted. 

 A control of this same wheat had 1 per cent smutted heads. 



II. CYLINDER INFECTION. 



1. Blossoming summer wheat (land wheat from Grabschen) was infected in the cylinder with 

 fresh loose smut of wheat. The harvested and sterilized seed was then sown in autumn of the same year, 

 directly in open ground. 



1,750 stalks developed, of which 8 per cent were smutted. 



An equally large control from seed of the same field, but from non-infected heads, showed 

 no smut. 



