INFLUENCE OF PHILIFPINE CLIMATE ON WHITE MEN. 429 



ippines, the task is beset with fewer difficulties and it is to the elucidation 

 of this problem that our efforts have been directed during the last thirty 

 months. The matter is of some practical importance in the selecting 

 of recruits and civil service employees for tropical countries. 



SOURCES OF EVIDENCE. 



The evidence on which this report is based is of several kinds and 

 derived from various sources. It may be divided into classes as follows: 



Class I. A series of observations carried out under the supervision of the 

 Board, during the calendar year 1909, on enlisted men of the United States 

 Army. This will be called the "1909-Group." One hundred and fifty-seven 

 blonds and 154 brunettes were observed. Besides the symptomatology and the 

 sick record over a period of two years for these men, there were made 1,100 

 weight, 1,320 pulse rate, 1,320 respiration rate, 1,320 temperature, 880 blood- 

 pressure and 880 dynamometer observations, spaced at equal intervals throughout 

 one year.' There were performed by the Board 195 red blood cell counts, 195 

 haemoglobin estimations, 38 leucocyte counts, and 57 differential counts. 



Class II. A series of observations carried out. under the supervision of the 

 Board during the calendar years 1910 and 1911 on enlisted men of the United 

 States Army. This will be called the "1910-Group." Three hundred and forty- 

 seven blonds and 346 brunettes were observed for one year. Besides recording 

 the sick record,* symptoms, effects of tropical residence and sunlight, habits as 

 to food and alcohol, characters, court-martial trials, fines and confinements, 

 there were made on the men, 3,694 weight, 3,986 pulse rate, 3,986 respiration 

 rate, 3,986 temperature, 2,540 blood-pressure and 620 dynamometer observations, 

 1,134 haemoglobin estimations, 1,134 red blood cell counts, 1,152 urine and 

 601 stool examinations.^ These observations were spaced at regular intervals 

 throughout- a year. There Avere performed by the Board 118 leucocyte esti- 

 mations, 90 diffferential blood counts, and 56 Ameth counts on blond and 

 brunette Americans, and, for comparison, 552 blood-pressure estimations on 

 386 Filipinos and 50 differential and Ameth counts on 50 Filipinos. 



Class III. A collection of data from the commissioned officers of the Phil- 

 ippine Scouts and the Philippines Constabulary and fi'om the Americans in the 

 Manila police force. These are men who have been a long time in the Philip- 

 pines, the average period of continuous tropical service being 5.5 years. There 

 were 186 blonds, 147 brunettes, and 235 of a mixed type in this group. As a 

 class they are men who do a large amount of work out of doors and exposed 



^ The observations referred to in this sentence were made under the super- 

 vision of the Board, by the following medical officers of the United States Army : 

 Major C. C. Collins and Captains C. D. Cowles, jr., G. L. McKinney, and 

 H. A. Phillips. 



* The sick record covered a period of over twenty-two months. 



'^ The observations referred to in this sentence were made under the super- 

 vision of the Board, by the following medical officers of the United States 

 Army: Majors A. E. Truby and Roger Brooke, jr.; Captains E. G. Bingham, 

 John R. Barber, Mahlon Ashford, E. G. Huber, H. M. Snyder, and W. L. Hart; 

 First Lieutenants J. B. H. Waring, W. R. Dear, C. E. Doerr, F. S. Wright, 

 C. G. Snow, N. L. McDiarmid, Armin Mueller, T. J. Leary, M. C. Stayer, L. C. 

 Garcia, and C. E. Fronk, Medical Corps; and First Lieutenants W. F. de 

 Niedman and C. A. Betts, Medical Reserve Corps. 



