352 



SCIENCE 



[N. S. Vol. XLII. No. 1080 



onies appearing in water samples were also tested, 

 but among 250 test cultures no exceptions were 

 encountered. Our conclusions of these exhaustive 

 tests are that the Eesculin-tailesalt test is thoroughly 

 reliable. Out of 1,200 samples analyzed only in 

 one case a wrong impression was obtained on ac- 

 count of the presence of some exceptional organ- 

 ism. A full description of this investigation will 

 appear in the Centralblatt fur Balcteriologie. 

 Numbers and Efficiency of B. bulgaricus Organ- 

 isms in Commeroidl Preparations Examined Dur- 

 ing the Period January-June, 191^: EuTH C. 

 Gkeathouse. 



The number and efficiency in acid production of 

 B. hulgarious in commercial preparations are an 

 index of the value of the preparations. 



Forty commercial preparations, the products of 

 twenty-three firms, were examined between Jan- 

 uary 15, 1914, and June 1, 1914. These samples 

 were collected fresh from the manufacturers and 

 held under conditions of temperature and humid- 

 ity which are practicable for commercial handling. 

 They contained, in the case of dry cultures, from 

 none to 250,000 living B. iulgaricus per gram; in 

 the case of liquid cultures, from 2,300 to 320,000,- 

 000 per c.c; in the case of sour milk drinks, from 

 800 to 790,000,000. 



The maximum acidity produced in milk by the 

 B. hulgaricus in these preparations varied from 

 1.20 per cent, to 3.41 per cent, acid calculated as 

 lactic. The ability of the B. hulgaricus to pro- 

 duce acid was decreased in the old preparations. 

 The amount of decreases averaged 38.5 per cent, 

 in the case of dry cultures kept on ice for two 

 months, and 26.4 per cent, in the case of liquid 

 preparations kept on ice for two weeks. 



The strains producing different degrees of acid- 

 ity were examined for differences in morphology, 

 staining properties and curd production in milk, 

 which would indicate that they were separate or- 

 ganisms, but no such differences were found. 

 Agglutination Studies of Milk from Cows Affected 

 with Contagious Abortion: L. H. Cooledge. 

 Milk studied was obtained from a herd in which 

 a high percentage of animals have repeatedly 

 given positive complement fixation and agglutina- 

 tion tests for contagious abortion and having a 

 record of frequent abortions. 



The milk from each quarter of 61 cows has been 

 examined at intervals during the last 6 months. 

 Of these the milk of 18 (30 per cent.) has given a 

 positive agglutination test with Bad. abortus, in 

 one or more quarters, at some time, or during this 

 period. The power of the milk of one quarter to 



agglutinate the abortion bacterium has been ob- 

 served to spread to another quarter and finally to 

 all four; it has also been observed to gradually die 

 out. Milk drawn at about the middle of the milk- 

 ing has the strongest agglutinating reaction. 



An attempt to demonstrate the presence of Bact. 

 abortus in milk that agglutinates the organism has 

 resulted as follows. Out of 18 quarters the milk 

 of which agglutinate the abortion bacterium the 

 milk of 14 produce lesions in guinea-pigs which 

 are like the typical lesions caused by a pure cul- 

 ture of Bact. abortus. 



In the 7 cows whose milk has gradually acquired 

 the power of agglutinating the abortion bacterium 

 during this experiment one or both of the rear 

 quarters have been the first to show agglutination. 

 This suggests contamination of the rear quarters 

 by genital discharges. 

 The Presence of Bacillus abortus in Milk: Alice 



C. Evans. 



Special methods of plating milk samples which 

 were drawn aseptically have shown that the ba- 

 cillus of contagious abortion occurs commonly in 

 certified milk in the vicinity of Washington, D. C, 

 and Chicago, 111. These organisms grow profusely 

 on serum agar plates. About 30 per cent, of the 

 samples of milk from two certified dairies near 

 Chicago, which were plated on serum agar, showed 

 this organism to be present in milk at the time of 

 dra-ning from the udder, in numbers varying from 

 110 to 4,300 per cubic centimeter. In one sample 

 taken from a herd which does not produce certified 

 milk, 50,000 of the Bacillus abortus were found 

 per cubic centimeter. This organism grows abun- 

 dantly in the cream layer, with the formation of 

 acid, but it grows sparingly in milk from which 

 the cream has been removed. Four per cent, of 

 lactic acid in the milk does not check the multipli- 

 cation of Bacillus abortus in the cream layer. 

 The Influence of Milk and Carbohydrate Feeding 



on the Bacteriology of the Intestine: Leo F. 



Eettger and Thomas G. Hull. 



The intestinal flora of white rats and of fowls is 

 determined in a very large measure by the diet. 

 White rats that were fed ordinary white bread 

 and green vegetable food exhibited an intestinal 

 flora which closely resembles that of man. Soon 

 after the diet was changed to mixed grain a, 

 marked transformation took place. When to the 

 diet of bread and vegetables a liberal amount of 

 milk or of lactose was added the ordinary mixed 

 flora quickly became simplified, and often pre- 

 sented the picture of only two or three types of 

 bacteria, namely B. bifidus of Tissier and B. acido- 



