316 SUMMARY OF CURliENT RESEARCHES RELATING TO 



Intestinal Flora of Sheep and Bovines.* — T. Choukevitch has 

 made an extensive study of the various bacterial types encountered in 

 the large intestines of these animals. He finds that the three dominant 

 types are coliform bacilli, enterococci, and streptococci. The latter 

 predominate in the caecum and upper part of the colon, but diminish 

 gradually in the succeeding portions of the intestine, until in the lower 

 part of the rectum they Ijecome extremely rare. Of other bacterial 

 types, classed as putrefactive, proteolytic, and acidophile organisms and 

 fermenters of cellulose, the author gives detailed descriptions. In 

 summing up the results of his findings, he states that on the whole the 

 nature of the bacterial flora in the horse and in the animals here con- 

 sidered is essentially similar. There are the same three dominant types, 

 and the same organisms capable of causing injury to the host should 

 they become predominant. Bacteria which are capable of fermenting 

 cellulose, hemicellulose, and starch, occur in the large intestines of aU 

 these animals, and their presence may indicate a relation between the 

 nature of the food and the characters of the flora. 



Bacterial Mutation. f — Reiner Miiller discusses the variations accom- 

 panying the artificial culture of various bacteria. In the case of 

 Bacterium coli mutabiJe, the growth upon litmus lactose-agar shows 

 papillae, daughter-colonies, composed of organisms incapable of fer- 

 menting lactose. Plate cultures of Bacillus paratyphosus B may show 

 two types of colony but no true papillae. The variation of different 

 bacilli under appropriate conditions may involve various physiological 

 and vegetative properties ; there may be alteration of the fermentative 

 powers, of the type of colony, of resistance to poisonous substances, of 

 pigment formation, of the morphological characters of the organism, of 

 its capacity to form spores, of agglutinability. A single type of organism 

 may show mutations in various directions. The power to vary may 

 disappear under certain conditions ; for example, B. coli miifabile, after 

 •prolonged culture upon gelatin, lost the power of forming papillae. The 

 causes of the variations are not understood, but it appears that the 

 newly acquired characters are stable, and capable of transmission to new 

 generations. The appearance of new ctiaracters, under certain condi- 

 tions, may afford a valuable means of diagnosis in the case of certain 

 organisms. 



Bacillary Septicaemia of the Caterpillars of Arctia caja L.J 

 r. Picard and (1. R. Blanc have found that this caterpillar when in- 

 fected becomes flabby and exhales a disagreeable odour. From the 

 blood they isolated a coccobaccillus in pure culture. This organism is 

 named Coccohacillus cajse : it is about 1 * 5 yu, long, motile, oval, stains well, 

 but not by Gram's method : the staining is polar with central clear space. 

 In bouillon it grows well at from 15-o5' ; the medium exhales the 

 odour of rotten eggs and acquires a greenish fluorescence. Gelatin is 

 rapidly liquefied. 



Pure cultures inoculated on healthy caterpillars killed in three days. 



* Ann. Inst. Pasteur, xxvii. (1913) pp. 246-63. 



+ Zeitschr. f. indukt. Abstamm. u. Veverbungs., viii. (1912) pp. 305-24. 



X Comptes Rendus, clvi. (1913) pp. 1334-6. 



