Acute lethal anaphylaxis in the intact rabbit is caused by a failure of the heart.
This failure of the heart is due to a change in the heart itself; it is peripheral and independent of the central nervous system for its production.
This change in the heart is shown anatomically and functionally by decreased translucency, change in consistency, and by failure to respond to stimuli, and is probably to be classed as a chemical rigor.
The rigor of the heart is most pronounced in the right ventricle, the wall of which may be gray, stiff, very tough to the finger nail, and non-irritable.
Cardiac stimulants of the digitalis group seem to exert a harmful effect when injected in acute anaphylaxis.
Blood coagulation is delayed; a loose clot forms after one half to two hours.
Anti-anaphylaxis is produced when the animal does not succumb to the injection.
When anaphylactic death is delayed for about one hour, a well developed rigor of the white muscles of the thigh, and of the diaphragm may occur while the animal is still alive.
Reasons are brought forward to show the necessity of more caution in employing the word anaphylaxis.
Friedberger's statement, that the lungs of guinea pigs dead from acute anaphylaxis are not characteristic of anaphylaxis for this animal, is shown to be baseless.