EARLY EMBRYONIC DEVELOPMENT OF THE HARDERIAN GLAND OF THE COMMON QUAIL (COTURNIX COTURNIX).

The present research aimed at giving a special focus on the early development of the Harderian gland - the principal orbital gland in birds. The development of the Harderian gland was studied in the common quail (Coturnix coturnix) at 7, 8, 9 and 10 days of incubation. The Harderian gland started its development as a long tube with a narrow lumen proximally and undifferentiated lumen distally at the seventh day of incubation, while at the eighth day of incubation, the studied gland differentiated into: the upper group formed from five opened tubules but the lower one consisted of three relatively closed tubules; the Harderian gland attained a strap-like appearance with hour-glass major borders, an increase in number of acini which share in formation of gland and its corresponding closed duct at the ninth day of incubation. More additional acini shared in formation of the Harderian gland. The tubular wide opened Harderian gland duct has appeared. Innervation of the Harderian gland was carried by the inferior ramus of oculomotor nerve at tenth day of incubation. [ABSTRACT FROM AUTHOR]