The discussion of this subject becomes difficult at its onset because we do not know its cause. The ablest investigators have diligently sought to determine its origin and to lay bare the mystery of its development, but thus far in vain. The inclination of some of the best scientific minds has been to assign a bacteriologic cause, and numerous parasites have been accused of being responsible for its production, but later investigations have not demonstrated their presence as constant.
Efforts have been made to associate the various manifestations artefact cell inclusion and cell degeneration with some specific germ, but the apparent discoveries of one have not been substantiated by other observers.
The researches of Farmer relating to the existence and separation of the chromatic elements seems to afford an explanation for the origin of the disease in chemical reaction, but whether the impetus be imparted to congenital embryonal cells or