l60 SUMMER DIARRHCEA 



liquefy gelatin, were at least twice as numerous in the faeces of 

 children suffering from diarrhoea as in those of healthy children, 

 but neither thej'^ nor O'Brien detected any type which largely 

 predominated. During the summer of 19 ii, when the disease 

 was very common, Alexander (19 12) carried out similar in- 

 vestigations in Liverpool, and Lewis (191 2) continued his 

 investigations in Birmingham. Alexander found non-lactose 

 fermenting bacilli in the fseces of 56 "/o of children suffering from 

 diarrhoea and in the fasces of 49 "/o of healthy children. Morgan's 

 No. I bacillus occurred in i3'2 7o of the former class and in 

 6-6 Vo of the latter. 



On the other hand Lewis, as the result of two years' very 

 careful and extensive work, came to the following conclusions : 

 "(i) The frequency of non-liquefying and non-lactose fermenting 

 aerobic bacilli in the faeces of children suffering from diarrhoea 

 is greater than in the faeces of normal children ; this fact is 

 suggestive that one or more types of this wide group of organisms 

 may have a causal relationship to the disease. (2) Absolute 

 proof of this relationship is still defective. (3) The evidence 

 adduced brings under such strong suspicion the possible causal 

 relationship of one variety, viz., variety 8 of the subgroup {a) of the 

 group G (i.e. Morgan's No. i bacillus) that further concentration 

 of research upon this variety is desirable." 



In 19 10 Lewis found non-liquefying, non-lactose fermenting 

 bacilli in the faeces of 21 (14V0) out of 146 normal children and 

 in the faeces of 47 {yy °/o) out of 62 cases of diarrhoea in children, 

 while in 191 1 they occurred in the faeces of 38 (3870) out of 100 

 normal children and in the faeces of 103 (95 "/o) out of 140 cases 

 of diarrhoea. In 1910 Morgan's bacillus was isolated from the 

 faeces of 30 "/o of diarrhoea cases, while in 191 1 it was isolated from 

 78 7o- In 1910 it was not encountered in any of the samples 

 of faeces from 146 normal children, but in 191 1 it was found 

 in the faeces of 17 out of 100 normal children. The organism 

 was also isolated from the heart's blood or spleen of 9 (64 "/o) out 

 of 14 children who had died of the disease. Feeding experiments 

 on rats, mice and rabbits showed that 23 (76 "/o) out of 31 strains 

 of Morgan's bacillus, whether isolated from the fasces of normal 

 children or of those suffering from diarrhoea, proved fatal to 



