The snake venoms and probably most of the animal toxins (zoötoxins) are very different substances. (See [Chapter XXIX.])
CAUSATION OF DISEASE.
This subject belongs properly in special pathogenic bacteriology. It will be sufficient to indicate that bacteria may cause disease in one or more of the following ways: (a) blocking circulatory vessels, either blood or lymph, directly or indirectly; (b) destruction of tissue; (c) production of non-specific poisons (ptomaines, bases, nitrites, acids, gases, etc.); (d) production of specific poisons (toxins).
ANTIBODY FORMATION.
Bacteria cause the formation of specific “antibodies” when properly introduced into animals. This must be considered as a physiological activity since it is by means of substances produced within the bacterial cell that the body cells of animals are stimulated to form antibodies. (See [Chapters XXVI–XXIX].)
STAINING.
The reaction of bacteria to various stains is dependent on their physico-chemical structure and hence is a result of physiological processes, but is best discussed separately ([Chapter XIX]).
CULTURAL CHARACTERISTICS.
The same is true of the appearance and growth on different culture media. ([Chapter XX].)