226 THE DISSEMINATION OF PATHOGENIC ORGANISMS BY FLIES 



and crushed B. paratyphosus A. was obtained. Similar results 

 were obtained from four flies examined on September 3rd. On 

 September 10th, three flies each seven days old were placed in 

 a sterile bottle, and from their excrement B. paratypliuiius A. was 

 recovered : the flies were then examined, tHe McConkey broth test 

 was negative, and the bacillus Avas recovered from the crushed flies. 

 On September 10th, a fly ten days old was examined but the 

 bacillus was not recovered ; it Avas recovered, however, from two 

 other flies also ten days old. 



From these experiments, which Faichnie appears to have care- 

 fully carried out, it will be seen that out of thirteen flies bred from 

 a typhoid stool six at least contained B. typhosus in their intestines, 

 and the bacillus was recovered from the excrement and intestine 

 of a fly sixteen days old. Similarly, from a paratyphoid stool at 

 least four flies out of eleven contained B. paratyphosiis A. in their 

 intestines and in each series of experiments one fly only was found 

 not to contain the bacillus. 



He also found B. typhosus in flies from Lahore, once ; from 

 Kamptee, twice ; from Nasirabad, once in flies from the bungalow 

 of an officer who had enteric fever, and once from flies in the 

 officer's mess there ; from Nowgong, twice, once in flies from the 

 Royal Artillery Coffee-shop, and again in flies from the trenching 

 ground ; making a total of nine times in three months. Except 

 in the case of the flies from Nasirabad, two flies were always 

 flamed before examination, and a control of the washed flies was 

 taken before crushing, so that there is no doubt that the bacillus 

 was actually in the interior of the fly most probably in the 

 intestine. 



Summarising the conclusions reached as the result of his first 

 series of experiments (1909) carried out at Kamptee, he says: 

 " Experience seems to show that infection conveyed by flies' legs, 

 natural though it may appear to all from experiments carried out 

 to prove its possibility, is not a common nor even a considerable 

 cause of enteric fever. On the other hand infection by the 

 excrement of flies bred in an infected material explains many 

 conclusions previously difficult to accept. In a word, it is the 

 breeding ground that constitutes the danger, not the ground where 

 the flies breed." 



