During my service in 1905 and 1906 in Dr. Gorgas' wards in Ancon Hospital, I was particularly interested in certain phases of malarial infections, and I analyzed the cases admitted during the six months of my service with reference to the following points :
1. Incidence of malarial infections and mortality.
2. Results of examinations of blood for malarial parasites.
3. The relative value of several systems of quinin administration.
4. The time of day when malarial paroxysms occurred.
5. Malarial immunity.
6. The quinin test in differentiating malarial from other fevers.
7. Chronic malaria or malarial cachexia.
INCIDENCE AND MORTALITY
There were admitted to the "white fever wards" during the six months 1,300 patients; 1,107 of these cases were clinically malarial. That is, at this time a little more than 85 per cent. of the morbidity among the whites was due to malaria. Among the 1,300 patients there were 15