The relatively young bouillon filtrates, 24 and 48 hours old, of certain strains of B. coli obtained directly from the ileum of scouring calves, were highly toxic for calves about 1 month old, as well as for older calves and cows when given into a vein. The symptoms, of panting followed by dyspneic and jerky respiration, indicate some at first obstructive action upon the alveolar and endothelial cells, followed by a greater permeability and eventual filling up of the air spaces with a serous, fibrinous, and hemorrhagic exudate. Similar effects are produced in other organs, such as liver and kidneys, if the toxin reaches them or is formed there by multiplying bacteria. There are no immediate or remote effects resembling those on calves following the intraperitoneal or the intracardiac injection of B. coli filtrates into guinea pigs even when the dose represents many multiples, per body weight, of the dangerous or even fatal calf dose.
The administration of the filtrate subcutaneously is without visible effect. Similarly, feeding large numbers of living bacilli produced no manifest disturbances.
In support of the hypothesis of a genetic relation between the group of B. coli and of paratyphoid, a similar but less severe effect was produced in a calf by the intravenous injection of a bouillon filtrate of a paratyphoid strain.