METHOD OF ISOLATING B. DYSENTERIC. 353 



quently succumb. Rabbits as a rule recover from subcutaneous 

 inoculation, which usually produces well-marked local swelling ; 

 but in two instances Flexner was able to cause death in rabbits 

 following upon subcutaneous inoculation, both with a Philippine 

 culture and with one of Kruse's, and in each animal lesions were 

 found in the colon quite analogous to those seen in the human 

 subject. Dogs generally die within 5 to 6 days after being fed 

 with cultures, developing well-marked diarrhoea, and post mortem 

 the large intestine is usually found to be much swollen. Monkeys 

 were found by Flexner to be most resistant, subcutaneous inocu- 

 lation producing only a local swelling, which rapidly passed away 

 and caused no apparent illness, even large doses of croton oil 

 followed by food contaminated with the bacilli failed to produce 

 infection. 



It will be seen that the evidence furnished is practically con- 

 clusive as to the causal relationship between this bacillus and 

 one form of dysentery, a form, moreover, which is both wide- 

 spread and embraces a large proportion of cases of the disease, 

 and especially of importance is the fact that observations made 

 independently in different countries have yielded practically 

 identical results on this point. 



Method of Examination. So far as is known the bacilli are 

 found only in the dejecta, especially amongst the small portions 

 of bloody mucous present therein in acute cases, and in the small 

 shreds of mucous membrane should these be found. In thirty- 

 six cases examined, Shiga obtained the bacillus in thirty-four 

 from the dejecta, and in two others post mortem from the 

 intestinal mucous membrane. Preferably agar plates are to be 

 employed in culture work, and these are to be incubated at 

 37 C. Vedder and Duval found that if colonies which appeared 

 after twelve hours were marked with a pencil, there was a 

 greater probability of obtaining the bacillus of dysentery from 

 those which appeared later, most of those appearing early being 

 colonies of bacillus coli. To attain an early recognition of the 

 nature of these later appearing colonies, it is recommended that 

 sub-cultures from them be made at once in glucose agar, thereby 

 differentiating the gas formers from the non-gas formers without 

 loss of time. It is desirable in conducting an examination to 

 obtain sufficient blood of the patient or cadaver to enable one to 

 carry out an agglutination test upon the isolated bacilli. In the 



