Morphometry and expression of immunoglobulins-containing plasma cells in the Harderian gland of Birds

Table 1: Species differences in gross and histochemical parameters of Harderian gland of birds ^[3, ^4, ^9, ^10, ^11, ^23, ^2]

Parameter	White leghorn	Native chicken	Rook	Canadian ostrich	Duck	Pigeon
Location	Ventro-medial to eyeball	Dorsal-posterior to eyeball	Ventral and posterior to eyeball	Ventro-medialto posterior part of the eyeball	Anterio-medial part of eyeball	Ventro-medial part of eyeball
Shape	Hourglass	Triangular	Tongue	Flattened	Arrow	Tear drop
Size	Length: 17.66 mm Breadth: 6.2 mm	Length: 9.2 mm Breadth: 5.1 mm	Length: 18.0 mm Breadth: 8.6 mm	Length: 35.3 mm Breadth: 15.65 mm	--	--
Color	Pale pink	Brownish	Pink yellow	Light pink	Pink	Brown to pink
Plasma cell	IgA more	IgG more	--	--	IgM more	--
Secretory mechanism	Apocrine	Holocrine	Merocrine to apocrine	Apocrine	Apocrine	Apocrine