Embryological Studies on the Oesophagus of the Domestic Fowl 1 On the Developmental Changes in the Oesophageal Epithelium

This report deals with the result of the examination on the development of the oesophagus of Single-comb White Leghorn. The materials were observed every 24 hours during 3～19 days from the beginning of the incubation. The same observation on the oesophagus of chicken was made on the 1st, 2nd, 4th and 30th day after hatching and compared with that of adult. Whole size of the oesophagus, size of the oesophageal lumen, thickness of the oesophageal epithelium, numbers of layers of the epithelium etc. were shown in table 1. The form of the oesophageal lumen in the 7-day embryo was cross-shaped. In the 8 day embryo the lumen had six folds and in the 9-day embryo seven. In the older ones than 14-day embryo, each fold was divided into two and their forms showed complex. The growth rate of the epithelium descended between the 7-day embryo and 14-day embryo, then ascended, extremely as regard that of 19-day embryo and the newly hatched chick. The primitive cells of the oesophageal gland were clearly found in the 7-day embryo. These cells surrounded a lumen in the 15-day embryo. The gland of 19-day embryo was as complete as in the adult.