Comments on Typical feather
i) A typical feather has a strong shaft and rachis and characterized
by the presence of interlocking arrangements of barbules.
ii) It consists of a small proximal calamus and upper distal portion shaft.
iii) The calamus is hollow and at its lower end contains a small aperture the inferior umbilicus and another superior umbilicus at the junction of calamus and shaft.
iv) Shaft or rachis is solid and opaque, forming the longitudinal axis of vane.
v) The vane is made up of two unequal lateral halves with its distal end narrower than its proximal end.
vii) Each lateral half of the vane consists of numerous narrow, parallel and closely spaced thread like structures called barbs with interlocking barbules.
Comments on Contour feather.
i) This feather forms the general covering of the body.
ii) These are small feathers having poorly developed barberles.
iii) The barbules can be easily isolated.
iv) The calamus is hollow and very small in comparison to typical feathers.
v) Inferior umbilicus lies at the proximal end of calamus.
vii) The rachis is well developed but doesn’t extend up to distal extremity of the vane.
viii) Both the halves of the vane are more or less equal in size.
