Notes
They do, however, take place, since within comparatively few years whole species have completely disappeared; for example, the great auk and the passenger pigeon. In these cases it is not known what part disease played in the destruction.
A tissue represents an aggregate of similar cells with the intercellular substances in relation with these as connective tissue, muscular tissue, etc. Where such cell aggregates are localized and where the cells are arranged in structures having definite form and size and performing a definite function, it is customary to designate such structures as organs, as the brain, liver, etc.
By cachexia is understood a condition of malnutrition and emaciation which is usually accompanied by a pale sallow color of the skin.
By trauma is understood a wound or injury of any sort.
The term exudation is used to designate the passing of cells and fluid from the vessels in inflammation; the material is the exudate.
By transudation is meant the constant interchange between the blood and the tissue fluid.
The interesting analogy between fermentation and infectious disease did not escape attention. A clear fluid containing in solution sugar and other constituents necessary for the life of the yeast cells will remain clear provided all living things within it have been destroyed and those in the air prevented from entering. If it be inoculated with a minute fragment of yeast culture containing a few yeast cells, for a time no change takes place; but gradually the fluid becomes cloudy, bubbles of gas appear in it and its taste changes. Finally it again becomes clear, a sediment forms at the bottom, and on re-inoculating it with yeast culture no fermentation takes place. The analogy is obvious, the fluid in the first instance corresponds with an individual susceptible to the disease, the inoculated yeast to the contagion from a case of transmissible disease, the fermentation to the illness with fever, etc., which constitutes the disease, the returning clearness of the fluid to the recovery, and like the fermenting fluid the individual is not susceptible to a new attack of the disease. It will be observed that during the process both the yeast and the material which produced the disease have enormously increased. Fermentation of immense quantities of fluid could be produced by the sediment of yeast cells at the bottom of the vessel and a single case of smallpox would be capable of infecting multitudes.
Flexner has recently succeeded in isolating and cultivating the organism of poliomyelitis, but the organism is so small that its classification is not possible.
The comparison here is with the atrium of a Pompeiian house.
This was the case of a woman, by occupation a cook, whose numerous exchanges of service were accompanied by the appearance of cases of typhoid fever in the families. This became so marked that an examination was made and she was found to be a typhoid carrier and as such constantly discharging typhoid bacilli. She is now isolated.
By structure as used in this wide sense, there must be understood not merely the anatomical structure, which is revealed by the dissecting knife and microscope, but molecular structure, or the manner in which elements are arranged to form the molecule, as well.