The anatomy of the cloacal bursa (bursa of Fabricius) in the helmeted guinea fowl (Numida meleagris galeata).

The cloacal bursa (bursa of Fabricius) in the guinea fowls appeared either as an oval blind sac with a short thick stalk in one group or had a pointed cranial blind end with a slightly bulging middle part that was followed by a thick caudal stalk in the other group. Both groups of bursae originated from the proctodeal wall of the cloaca and were placed dorsal to the rectum. The average length of the bursa was 18 mm while the average width at the mid section was 15 mm. The internal surface showed about 12-14 primary folds. Histologically, the outline of the bursa was well established by day 18 of incubation. The primary folds had also been formed. Lymphocytes had already been encountered within the framework of the bursa at this day. The epithelium bordering the tunica propria was composed principally of two layers of cuboidal cells. Epithelial buds had also formed and some were already detached from the epithelial lining. The blood vessels present were positioned just beneath the outer covering. At day 19 of incubation, most of the epithelial buds had two layers of cells arranged in a circumscribed manner while a few had three layers of cells. Blood vessels had increased in number and were deeper placed inside the bursa than previously. At day 20, the cells of the upper layer of the epithelium were dorsoventrally flattened and stained paler than the cells of the lower layer. It was possible to distinguish the cortex from the medulla and the basement lining between both zones was distinct. Tiny vesicles within the cytoplasm of the epithelial cells at the mucosa and follicles were observed. Macrophages were also observed within the gland. At day 21, blood vessels were observed in the cortex of the follicles. The maximum number of primary folds (14) had been formed. At day 22, several follicles had severed connections with the mucosal epithelium. The mucosal lining had dropped to a single layer of cells in some areas. Goblet cells were observed amongst the mucosal cells. A plasma cell had first appeared. By day 25, dead cells had increased quite in number and there was also an increase in number of medium and small-sized lymphocytes within the gland. By day 26, the upper layer of the surface epithelium was composed primarily of tall columnar cells with numerous large vacuoles. Macrophages had suddenly increased within the thin interfollicular spaces and most of them were crowded internally with various sizes of debris.(ABSTRACT TRUNCATED AT 400 WORDS)

The structure of the harderian gland of the guinea fowl at embryonic and post embryonic stages.

The Harderian gland of the guinea fowl is a bright, pink and relatively large orbital organ situated at the ventromedial aspect of the orbit. It possesses a single duct that has its exit on the convex medial surface. The outline is irregular with its caudal half narrower than the rostral half, and possessing a slight constriction about the mid point. Histologically, the gland had been outlined with the existence of a large contorted lumen by day 18 of incubation. The surface epithelial lining showed two layers of cells all through and lymphocytes were also present. By day 19 of incubation, certain zones of the surface epithelium had become pseudostratified and some of these cells contained vacuoles indicative of secretory materials within their cytoplasm. By day 21, few definitive acini with lumina had been observed and at day 23, the epithelium had assumed only a single layer of cells that were tall columnar cells, except at the junctions of the folds. By day 24, the tunica propria seemed to have completely disappeared with the acini occupying every available space. Plasma cells were seen three days after hatching.

The submucosal glands and the orientation of the musculature in the oesophagus of the camel.

The histological structure of the oesophagus of the camel in different parts of its course was investigated with tissues from seven camels, and with haematoxylin and eosin and Masson's trichrome stain. Gross dissections confirmed the orientation of the muscle fibres in the tunica muscularis. The epithelium showed heavy cornification. Many submucosal mucous glands were found throughout the length and all round the wall of the oesophagus. This was contrary to what has been reported generally for ruminants. The lamina muscularis mucosae was in the form of small scattered strands of smooth muscle (more readily identifiable with trichrome stain) and only in the caudal oesophagus. It did not form a continuous layer here. The tunica muscularis was of striated type throughout which agreed with what has been found in the other ruminants. Its fibres, however, were differently oriented. The outer tunica was mainly circular (especially in the mid-thoracic part) and the inner one was mainly longitudinal in direction. Mixed orientation of the muscle fibres in parts of the same section was also noticed. These findings have not been reported previously in the camel.