NORTH DAKOTA. 211 



in different varieties. The legislature contributed $3,000 for the 

 laboratorj^ work of this line of investigation. 



In studying the nutrition of the wheat plant in its relation to soil 

 conditions, special attention was given to humus, the development of 

 efficient methods, the relation of conditions of soil to its formation 

 and character, and the availability of the plant food in humus. 



The swamp-fever investigation made good progress. It was found 

 that cases in horses otherwise appearing to be entirely healthy may 

 be infectious for a long time without showing clinical evidence 

 except a periodical rise in temperature. The results have further 

 shown that the disease is transmissible by subcutaneous and intra- 

 venous injection and the ingestion of blood coming from affected 

 horses, and that the etiologic factor is an ultramicroscopic or filterable 

 virus. The popular conception of swamp fever as being essentially 

 an anemia was shown to be erroneous. No efficient therapeutic agent 

 has thus far been found. 



The work on disease-resistant flax now carried on in cooperation 

 with farmers has shown that the varieties selected are not only 

 strongly resistant to diseases but that they are also especially good 

 yielders even upon new lands. The results of investigations on the 

 relation of bacteria and fungi in soil to cropping 'methods are con- 

 sidered as showing that the early deterioration of the wheat crop on 

 new lands is not necessarily due to the chemical depletion of the soil, 

 but to the introduction of special parasitic fungi which bring about 

 soil sickness in the same sense that flax soils become sick. Attention 

 was also given to the methods of the distribution of these diseases 

 and the means of their eradication or prevention. It is pointed out 

 that some of these wheat diseases attacked quack grass, and that this 

 seems to explain the strong influence that a quack-grass soil has in 

 preventing the growth of wheat upon the same area. Observations 

 on sterilized soil from the rotation plats showed that the bacteria 

 content soon came back to the original but that the disease fungi 

 returned less rapidly. Work was also taken up during the year on 

 the changes taking place in flax during the process of ripening, and 

 in connection with the retting of flax fiber and on the products of dis- 

 tillation from flax straw. 



Under the Hatch Act the agriculturist gave considerable attention 

 to plant breeding and seed distribution, dry-land cooperative trials, 

 and animal husbandry work. The work in plant breeding was 

 greatly enlarged, particularly in breeding corn, alfalfa, and winter 

 grains. The yields of corn in ear-to-row tests ranged from 96 to 

 37.7 bushels per acre. Golden Dent No. 950 seed corn was widely 

 distributed by various means, though largely through sales direct 

 from the institution. 



