Normal Growth of the Bursa of Fabricius in Chickens

Abstract

THE bursa of Fabricius is a blind sac connected to the dorsal aspect of the cloaca at its junction with the large intestine. The bursa, as reported by Jolly (1913 Jolly (1914), grows rapidly up to the 4th month after hatching and then decreases in size. The maximum size attained by the bursa, according to Schauder (1923), is 2 to 3 cm. long and 15 cm. wide at 4 to 5 months of age. Recent statements in the literature (Kaupp, 1933; Bradley, 1950; Hinshaw, 1953; and others) concerning bursa growth and atrophy appear to be based on the report of Jolly and possibly also Schauder. Histologically the bursa not only resembles a lymph gland with lymph follicles, but also contains pseudostratified columnar epithelial cells (Calhoun, 1933). In both growth and histological structure the bursa resembles the thymus and has been nicknamed the “cloacal thymus.” Riddle (1928) found that in the Ring …