ptiloses

Noun

ptilosis (usually uncountable, plural ptiloses)

1. (usually) The appearance or study of feathers on a bird, including factors such as their texture or shape.
   • Pterylography must be based on the distribution of the follicles, for the ptilosis as seen externally does not reflect the actual pterylosis.2013, Donald S. Farner, Avian Biology, volume 2, page 31
2. (usually) Loss of the eyelashes, due to ulceration or other damage to the follicles.
   • The state of the lid, when deprived of the eyelashes, has been called ptilosis or alopecia ; the effect of the removal is very inconsiderable, and unless you look closely to the lid of a person of light hair, you can hardly distinguish whether the eyelashes are wanting or not.1826, The Lancet - Volume 10, page 323