Results obtained in the greenhouse indicate that loosening the com- 

 pact subsoil and placing lime and fertilizer in the deeper layers resulted 

 in a greater concentration of fibrous roots of alfalfa and ladino in those 

 layers. 



L. T. Kardos 



OTHER ACTIVE PROJECTS 



Influence of the Level of Available Potash in the Soil 

 on the Longevity or Persistence of Clover in Hay Stands 



R. L. Donahue 



Proper Width and Slope of Beds for Draining 

 Whately and Biddeford Soils 



A Survey of the Soils of New Hampshire 



W. H. Lyford 

 W. H. Lyford 



Bacteriology 



Studies on Bovine Mastitis 



The characteristics of staphylococci causing bovine mastitis were in- 

 vestigated. Cows which were free of all mastitis infection were injected, 

 via the teat canal, with different strains of mastitis staphylococci. It was 

 demonstrated that staphylococci producing alpha and l)eta toxins caused 

 acute cases of mastitis. A strain which formed only beta toxin did become 

 established when injected into quarters of a test cow, but no clinical evi- 

 dence of infection developed. It was further demonstrated that the alpha 

 toxin was highly irritating to the mammary tissue when injected into the 

 udder, via the teat canal. Typical cases of acute mastitis developed follow- 

 ing the injection of this type of toxin. The beta type of toxin was essen- 

 tially nontoxic when injected into the udder. 



In one of the dairy herds under study, the infection spread to new 

 quarters at the rate of about 20 percent per year. Proper disinfection of 

 the teat cups appears to have appreciably reduced the spread of this in- 

 fection. 



Studies are still in progress in an attempt to find drugs that will cure 

 long-standing, chronic cases of bovine mastitis. 



L. W. Slanetz 



Studies on a Cellulose-digesting Spore-forming 

 Anaerobic Bacterium Isolated from the Bovine Rumen 



Bacteriological studies were carried out on a microorganism isolated 

 from the bovine rumen. The organism was isolated using selective media 

 containing cellulose, and the purity of the culture was determined by sub- 

 sequent transfers in glucose and cellobiose agar media. The organism was 

 slightly curved, gram-negative rod which freciuently produced oval, re- 

 fractile spores. Cells were 0.3-0.7 u. in diameter, 3-5.2 u. in length. Spores 

 were 1.0 u. in diameter. The organism was an obligate anaerobe requiring 

 a low oxidation reduction potential for growth. The cultural and bio- 

 chemical properties of the organism were examined. A growth medium 



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