The etiology of leukemia, although studied in detail by numerous investigators, still remains obscure.
Malaria, pregnancy, syphilis, splenic trauma and tuberculosis are regarded by many as the exciting agent. Whether these conditions are causative or merely coincident cannot be definitely ascertained at present, owing to the comparatively rare incidence of the disease, and the relatively small number of cases thus far reported.
Still others believe that the condition is due to a specific micro-organism. Ward,1 who has made an intensive study to determine whether or not infection is the cause, came to a negative conclusion, basing his opinion on these observations:
There is a congenital form of leukemia found in children of normal parents.
Leukemic parents have never been known to transmit the disease to their offspring.
Very few instances of supposed transmission of the disease have occurred.
Leukemia has a marked preference for a particular age and sex,