548 



SCIENCE 



[N. S. Vol. XXXIII. No. 849 



points Iq common with the typhoid bacillus. It 

 may be cultivated easily on the ordinary labo- 

 ratory media, but its growth on slant or plate agar 

 is delicate, and very much like that of the Strepto- 

 coccus pyogenes. This peculiar appearance on 

 agar is a great aid in the identification of the 

 bacillus, and hence in the diagnosis of the disease. 



This organism, which has been named Bacterium 

 pullorum, IS present in the intestine, liver, lung, 

 spleen, kidney, heart and unabsorbed yolk of 

 chicks suffering with the disease in question. It 

 is to be obtained most easily from the liver and 

 yolk, when the latter is present. 



Feeding experiments conducted on a large scale 

 demonstrated that the disease may be transmitted 

 to young chickens under three days old through 

 infected food and drinking water. Furthermore, 

 chicks may be infected with Bacterium pullorum 

 before hatching. These two facts furnish an easy 

 explanation as to the rapid spread of the infection 

 among chicks many of which were normal at the 

 time of hatching. 



The mother hen is the source of infection in the 

 egg. The examination of hens from which it was 

 almost impossible to raise chicks, on account of 

 white diarrhea, revealed the fact that the ovaries 

 were infected with Bacterium pullorum. The dis- 

 eased ova were very abnormal. They were discol- 

 ored, misshapen and of all degrees of consistency. 

 Eggs from these hens had been found to contain 

 the specific bacillus in question in all stages of 

 incubation. Later, a method was devised for 

 identifying the bacillus in fresh eggs which came 

 from infected flocks. Numerous eggs were tested, 

 and the organism was observed in many of them. 

 Thus, a satisfactory method is at hand for deter- 

 mining, without injury to the birds, which hens 

 are infected with Bacterium pullorum, and conse- 

 quently are the source of infection, if their eggs 

 are used for hatching purposes. 



Quite recently a pullet which was less than eight 

 months old, and which was one of the survivers of 

 an infected flock, showed the presence of the 

 specific bacillus in the ovary. This discovery com- 

 pleted the cycle of infection. The laying hen is a 

 bacillus carrier. Her eggs harbor the bacillus, 

 and the chicks which are hatched emerge with the 

 organism planted within them. These chicks are 

 the source of infection of other chicks which are 

 normal at the time of hatching. The disease be- 

 comes epidemic. The female chicks which survive 

 carry the infection in their body until they are 

 mature laying hens, and the same cycle is begun 

 again, unless intelligent steps are taken to eradi- 



cate the infection by methods which are most 

 apparent. 



Carbolio Acid in Fowl Cholera: Philip B. Hadley. 

 The prevalence of fowl cholera in many of the 

 New England states is increasing. An attempt is 

 being made at the Ehode Island Agricultural Ex- 

 periment Station to devise methods for its pre- 

 vention or control. Preliminary experiments have 

 involved a study of the effects of subcutaneous 

 inoculations of a 5 per cent, solution of carbolic 

 acid upon fowls previously infected with the or- 

 ganism of fowl cholera. Bacillus iipolaris septicus. 

 The results of this work to date have shown that 

 repeated daily subcutaneous inoculations with 5 

 per cent, carbolic acid, in 3 c.c. amoimts, have 

 power to prevent the development of the disease in 

 fowls infected from one to twenty-four hours pre- 

 viously with the cholera organism. The results 

 were approximately the same whether the infec- 

 tions resulted from subcutaneous inoculation of 

 the virus or from the ingestion of virulent ma- 

 terial (feeding by glass pipettes). The possible 

 manner of action of the carbolic acid was dis- 

 cussed. A more detailed report of this work ap- 

 pears in Ehode Island Agricultural Experiment 

 Station Bulletin, No. 144. 



The Etiology of Contagious Abortion of Cows: 



W. J. MacNeal. 



The existence of a contagious form of abortion 

 in cattle has been recognized for a long time by 

 practical husbandmen. Nocard (1886) made the 

 first extensive bacteriological investigation of the 

 disease, but failed to identify any microorganism 

 as the cause. Bang (1896) found a small bacillus 

 in the uterine exudate of aborting cows, grew it in 

 pure culture, and produced abortion by injecting 

 these cultures into cows and sheep. The peculiar 

 oxygen requirement of the microorganism for 

 growth in artificial culture was discovered and 

 fully studied by Bang and Stribolt. Subsequently, 

 the same organism has been isolated from cases 

 of contagious abortion of cattle by Preisz (1902) 

 in Budapest, Nowak (1908) in Krakau, Me- 

 Fadyean and Stockman (1909) in England, Mac- 

 Neal and Kerr (1910) in Illinois, XJ. S. A., and 

 by Zwick (1910) in Germany. 



The microorganism is a very small rod, not 

 motile and without spores. It is Gram-negative. 

 Plate cultures are best obtained by streak inocula- 

 tion on solidified serum-agar, the plates being in- 

 cubated at 37° in a closed jar from which the 

 oxygen is partly exhausted. This is conveniently 

 accomplished by putting plates of B. subtilis in 



