88 INFECTIONS OF THE DIGESTIVE TRACT 



a great difference in the numbers of anaerobes in the two 

 groups, the number of these organisms being greater 

 in the case of the carnivora. 1 Some observations of 

 interest on the flora of dogs we owe to Lembke, 2 who 

 found distinct differences between the flora after a diet 

 of bread and after one of meat. Of especial interest is 

 the fact that a bread diet rendered the faeces much 

 richer in anaerobes than did a diet of meat. The bacteria 

 observed upon the diet containing a great abundance of 

 fat resembled closely those noted on a bread diet. The 

 changes which are induced by alteration in the diet are 

 said by Lembke to be generally of a temporary sort. 

 On this subject he speaks hi the following way: "If 

 the diet is changed, there appear on the fsecal plates 

 new colonies of the most varied sort. In the course of a 

 few days these are materially reduced and the colonies 

 of B. coli again gain the upper hand." It appears that 

 with almost any change in diet new varieties of bacteria 

 are introduced in large numbers and somewhat obscure 

 the predominance of the colon bacilli in the fsecal 

 fields. Very soon, however, the colon bacilli regain their 

 original predominance, doubtless owing to the fact that 

 they are better able to adapt themselves to the nutrient 

 conditions than are the facultative forms which have 

 been introduced. Lembke states that if one limits the 

 entry of bacteria by sterilization of the diet, the foreign 



1 Escherich found in a young dog whose milk-fseces flora was 

 very similar to that of normal nurslings, that after a pure meat 

 diet there was only an extremely small proportion of colon bacilli, 

 whereas there appeared large numbers of liquefying colonies. 



2 "Beitrag zur Bacterienflora des Darms," Archiv f. Hyg., xxvi, 

 p. 325, 1896. 



