344 
JOHN M. PARKER. 
These micro-organisms “ may have begun their work out¬ 
side the body by developing in the milk, and so causing ab¬ 
normal products of decomposition or fermentation, possibly 
poisonous ptomaines.” 
These abnormal products of decomposition or poisonous 
ptomaines affect principally the nervous centers and cause the 
severe nervous depression and heart failure usually seen in 
these cases. 
Baruch also believes “ that the summer diarrhoea of in¬ 
fants is chiefly ; though not solely, due to the ingestion of 
micro-organisms, which create in the gastro-intestinal tract 
conditions analogous to those found in wounds, to which 
septic material has had access.” He further argues that un¬ 
sanitary conditions, poverty, filth, etc., are entitled to be 
placed only among the predisposing causes. The indigesti¬ 
bility of casein of cows’ milk by artificially fed children is of no 
importance, since in winter this is borne without serious con¬ 
sequences.” He concludes that the kind of food, if it be 
reasonably constructed, has little to do with producing diar- 
rnceal disease, provided the access of micro-organisms in its prep¬ 
aration can be prevented. 
Rachford also holds: First. — “ That the chief, if not the 
only, direct cause of ‘ summer complaint ’ is abnormal intesti¬ 
nal fermentations of food stuffs. These are always caused by 
bacteria. 
Second. — “ At present we are unable to make an exact 
astiological classification of these diseases, but it is probably 
true that there are quite a number of pathogenic bacteria, 
each capable of producing definite changes in the food which 
will cause characteristic symptoms. 
Third.—“ The disease being of bacterial origin it is neces¬ 
sarily infectious. It is probable that not all the diseases em¬ 
braced under the general term are equally infectious.” 
This writer believes that bacteria may cause disease in 
any one of three ways: 
First. — “ By interfering with the growth and function of 
bacteria normal to the intestine. In this way bacteria which 
do not produce poisonous ptomaines or irritating products 
