15)19] POODS III MAN KUTRITION. 867 



substituted or asymmetrical ureas could be detected. Triniefhyiamin w »» 

 completely demethylated, and the ammonia formed coorerted Into ui 



Contributions to the physiology of the stomach.— XLI, The alleged in- 

 fluence of the removal of the salivary glands on the secretion of gastric 

 juice, A. M. Swan. son {Amer. Jour. Phgaiol^ }.; »/.'/;?., ,\<.. ft. ;,,, //, figs. 



3). — Experiments carried out to determine whether <>r m>t a hormone exists 

 In the salivary glands affecting the Becretion ol gastric Juice by way of the 

 blood are reported. The conclusions reached are as follows: 



"... [The] results contradict the theory of a hormone la the salivary 

 glands stimulating the secretion of gastric juice. Extirpation of the salivary 

 glands in the dog does not decrease the gastric juice secretion (appetite and 

 secretagogue juice). 



"Extirpation of the salivary glands causes a distinct rise in the acidi;. 

 the gastric juice. This increase in acidity is greater than an be accounted for 

 by the slight increase in the rate of secretion. The slight Increase In quantity 

 may he due to the absence of the alkaline saliva. 



"After extirpation of the salivary glands, the maximum secretion rate after 

 a meal appears slightly retarded. This may be due to the absence of the warer 

 of the saliva, and to decreased psychic secretion, owing bo tin- drying of the 

 mouth and consequent impaired taste." 



Other work by Carlson has been noted (E. S. R. 34. p. 463; 40, p. 27m. 



The regulation of the intestinal flora of dogs through diet. J. 0. Torrftt 

 (Jour. Med. Research. 39 (1919), No. 3, pp. .il5-/,l f 7).—The study reported is 

 an attempt to demonstrate by experiments with dogs the transforming in- 

 fluence of various food materials on the intestinal flora. The investigation 

 includes determinations of the comparative transforming Influence of various 

 sugars and starches and of animal and vegetable proteins on the bacteria 

 within the intestinal tract and of the influence of fat in the diet en the Dum- 

 ber and types of bacteria. 



The results in general demonstrate that not all carbohydrates have an equal 

 tendency to establish a purely fermentative intestinal flora, ami not all protein 

 foods encourage putrefactive conditions in a like degree. Fat seemed to play no 

 part in determining the development of bacterial types in the Intestine, the only 

 effect of large amounts of fat of animal origin apparently being a reduction in 

 the relative number of certain bacteria. 



Lactose and dextrin, when added to a meat and rice diet, caused a marked 

 development of aciduric bacteria of the Bacillus acidophil** type to the almost 

 complete suppression of proteolytic types. Glucose and maltose exercised no 

 transforming influence on the types of bacteria present in the intestinal tract. 

 Sucrose, when fed in large amounts, caused a moderate increase in the numbers 

 of obligate fermentative bacteria and a partial suppression of proteolytic types, 

 but to a much less extent than lactose or dextrin. 



With commercially pasteurized milk (grade 0) the results obtained varied, 

 depending upon whether the milk was fed boiled or unboiled. With unboiled 

 milk, B. coli and streptococci predominated, while with boiled milk streptococd 

 and B. acidophilus predominated. Starchy foods all tended to s inplify the In- 

 testinal flora with the elimination of obligate putrefactive bacteria. EUee 

 proved less effective than bread, potatoes, ( , r beans as an antiputrefactive 

 agent. 



The proteins of the mammalian tissues were the onlj ones which eneoun 

 to any extent the growth and activity of the obligate putrefactive bacteria 

 within the intestinal tract. A diet of fish brought about a predominance of bac- 

 teria of B. eoli and B. proteus groups, while the B. loeJeM types pred omina n t 



