DISEASES PREVALENT IN THE ARMY 293 



duty in the front line again they did their part somewhere in 

 the rear, in the Service of Supply of the armies. 



It had been estimated, early in the war, that about 10 per 

 cent, of cases admitted to hospitals in the A. E. F. were of this 

 nature, and that about 60 per cent, of these had been returned 

 to duty. It was also frequently noted that a neurosis rarely 

 occurred in a wounded man, and that they were exceedingly 

 rare in colored soldiers. It is doubtful if these were so numer- 

 ous as that, for there were only 3795 cases reported as such 

 during 1918, and even if 4266 cases of hysteria are added the 

 sum would be only 8061 out of a total of 82,289 diagnoses 

 reported during the year. On the whole, the American Army 

 was relatively free from these conditions, and this was due 

 principally to the fact that we profited from the experience of 

 our Allies and excluded from the ranks of our army as many 

 as possible of these who would be more liable to develop such 

 neuroses. At each training camp and mobilization center was 

 stationed a board consisting of one or more psychologists and 

 psychiatrists, and, as a result of their examinations of the re- 

 cruits as they arrived from their homes, all the weak-minded, 

 mentally diseased and the neurotic were eliminated. This not 

 'only reduced the number of cases of war neuroses, but also 

 kept down our military offenders and criminals. No army in 

 history was so free from crime, both large and small, as the 

 American Expeditionary Force. 



INFECTIOUS DISEASES DURING THE WAR 



In the study of the infectious diseases, one of the fundamen- 

 tals is the problem of the healthy human carrier. In the ordi- 

 nary course of events a person who is infected with some 

 pathogenic organism develops the particular disease caused by 

 the microorganism in question, and he exhibits a more or less 

 typical picture of the disease, and either recovers or succumbs 

 from the infection. If he succumbs we can often demonstrate 

 the presence of the causative microorganism in the blood and in 

 many of the tissues at autopsy, often in enormous numbers. If 



