. Birds in flight . How are they fixed to the skeleton ? To see this all thesmaller feathers and the muscles, or flesh of the wingmust be removed. It will then be found that the flight-feathers are divisible into two series. One, widely spaced,runs along the upper surface of the forearm: the other,closely packed, along what answers to the back of the effect this is but a single rod of bone, but it is composed ofthree elements, answering to three of the digits of the humanhand—^the thumb and the first and second fingers. Butthey are scarcely recognizable as such, for the thumb isreduced
. Birds in flight . How are they fixed to the skeleton ? To see this all thesmaller feathers and the muscles, or flesh of the wingmust be removed. It will then be found that the flight-feathers are divisible into two series. One, widely spaced,runs along the upper surface of the forearm: the other,closely packed, along what answers to the back of the effect this is but a single rod of bone, but it is composed ofthree elements, answering to three of the digits of the humanhand—^the thumb and the first and second fingers. Butthey are scarcely recognizable as such, for the thumb isreduced to a mere stump, while the two fingers have becomewelded together. The third finger, indeed, has becomereduced to the palm-bone, and a short stump answering tothe first finger-joint. To this frame-work, which can be foldedup into the shape of a Z when the bird is at rest, the quills arefixed by their base by means of slender, but very strong elastictendons. In birds which have a long upper arm-bone, like ■w/..
Size: 1334px × 1872px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbirds, bookyear1922
