434 



SCIENCE 



[Vol. LV, No. 1425 



of tie casein preventing the formation of a 

 solid coagulum. In cultures of the South Da- 

 kota organism, on the other hand, there is 

 usually no visible change in plain milk for 

 about three weeks, after which, in varying 

 lengths of time, the fluid becomes solid. Some 

 days after coagulation there is an extrusion of 

 whey and finally peptonization begins, pro- 

 gressing very slowly however. Bacterium 

 phaseoli produces tyrosin crystals in abundance 

 in milk but none have been observed in cul- 

 tures of the South Dakota organism. The 

 latter produces a wide, deep yellow rim (Ridg- 

 way's primuline yellow loe. cit.) which is very 

 striking. 



Both organisms liquefy gelatin but Bac- 

 terium phaseoU does it rapidly whereas the 

 South Dakota organism does it so slowly that 

 for the first month there is little or no liquid 

 gelatin present, evaporation taking place al- 

 most as rapidly as the liquefaction. 



Another good medium for differentiating 

 these two organisms is Congo Red agar. Both 

 organisms take up the stain to a greater or less 

 degree and finally change the agar to a pur- 

 plish color but Bacterium phaseoli makes a 

 very thick, smooth, wet-sliining growth and 

 the South Dakota organism only a very meager 

 one. This medium is prepared as follows: 

 1000.00 c. c. distilled water; 10.00 g. saccha- 

 rose; 1.00 g. dipotassium phosphate; 0.20 g. 

 magnesium sulphate; 15.00 g. agar flour; 0.10 

 g. Congo red (Grii bier's). Steam the water 

 and salts one half hour, then add Congo red. 

 Filter through cotton and tube. Autoclave 

 tubes fifteen minutes at 115° C. 



The bacterium causing the wilt is a polar 

 flagellate rod 2-3 to 3jx by 1-3 to 1-2\l occurring 

 singly or in pairs, and has been named Bac- 

 terium flaccumfaciens nov. sp. 



Florence Hedges 

 Laboratory of Plant Pathology, 

 Bureau of Plant Industry, 

 Washington, D. C. 



THE PERIPHERAL CIRCULATION IN 

 MUSCLE INJURY SHOCK 



The following experiments were undertaken 

 in an attempt to determine the influence of the 



peripheral tone in the production of the low 

 blood pressure initiated by muscle injury. Evi- 

 dence has been presented by a number of ob- 

 servers indicating that the vasomotor center is 

 still active in shock produced by the exposure 

 of the viscera or aortic occlusion, and that some 

 peripheral tone is maintained.^ A recent paper 

 by Erlanger, Gesell and Gasser- presents re- 

 sults of a series of experiments in which, in 

 these types of shock, the condition of peri- 

 pheral constriction was dii-ectly determined by 

 the rate of perfusion through the arterioles and 

 capillaries. They show that during the devel- 

 opment of shock the peripheral resistance is 

 increased, and that only after the arterial 

 pressure has fallen is there a loss of vasomotor 

 tone, and consequently that a loss of tone is 

 not the primary cause of shock. Our results 

 are in accord with these findings and are pre- 

 sented as evidence indicating that the nervous 

 factor is of minor importance in the causation 

 of the low blood pressure following muscle 

 injury, as in other fonns of shock. 



The method of determining the relative con- 

 dition of vasomotor tone was that described by 

 Bartlett,^ and used by Erlanger, Gesell and 

 Gasser. The rate of inflow of a fluid at con- 

 stant pressure through the femoral artery of 

 one hind limb was determined at intervals dur- 

 ing the development of shock. The inflow 

 cannula was placed in a side branch of the 

 femoral artery or low down on the main branch 

 directed towards the heart. With this awange- 

 ment, through the use of clips on the arteries, 

 it was possible to shift quickly from the natural 

 blood supply of the area supplied by the intact 

 branches of the femoral artery to the perfusion 

 fluid and vice versa. The perfusion fluid was 



1 Porter: Am. Jour, Phys., 1907, XX: 399. 

 Porter and Storey: Ihid., 1907, XVIII: 181. 

 Porter and Quinby: Ibid., 1908, XX: 500. Seelig 

 and Lyon: Jour. A. M. A., 1909, LII: 45; also 

 Jour. Surg. Gynecol, and Obstet., 1910, 146. 

 Seelig and Joseph: Jour. Lai}, and Clin, Medicine, 

 1916, I: 283. Mann: Johns Hoplcins Hosp. Bull., 

 1914, XXV: 205. Morison and Hooker: Am-. 

 Jour, of Phys., 1915, XXXVII: 86. 



2 Erlanger, Gesell and Gasser: Am. Jour, of 

 Phys., 1919, XLIX: 90. 



3Bartlett: Jour. Exp. Med,, 1912, XV: 414. 



