Abstract
Minute coccobacilliform bodies have regularly been found in the nasal exudate of fowl infected both by injection and by contact with the coryza of slow onset. These bodies are commonly less than 0.5µ in diameter and are predominantly extracellular. They have consistently failed to grow in artificial media. They are held back by Berkefeld V filters which are impermeable to Hemophilus gallinarum but may pass through filters which are permeable to the test organism. The coccoid bodies are morphologically similar to a cultivable non-infective bacterium which may occasionally be isolated from exudate of the infected fowls.