57. Back (includes 58, 59).
58. Upper back.
59. Lower back.
60. Rump.
61. Mantle (back and wings together).
62. Breast.
63. Abdomen (includes 64, 65).
64. Epigastrium.
65. Belly.
66. Crissum.
E. Tail.
70. Tail feathers (or rectrices).
72. Upper tail coverts.
73. Lower tail coverts.
F. Wings.
75. Primary quills.
76. Secondary quills.
77. Bend of wing.
79. False wing (alula).
80. Scapulars.
86. Primary coverts.
89. Secondary coverts (include 92, 93, 94).
92. Greater wing coverts.
93. Lesser wing coverts.
94. Middle wing coverts.
95. Edge of wing.
G. Legs.
97. Thigh (concealed under skin).
98. Shin (tibia).
103. Heel joint.
103½. Tarsus.
112. Foot.
116. Toes.
126. Outer toe.
127. Inner toe.
128. Middle toe.
129. Hind toe.
For the purpose of defining the form, markings, coloration, and other
peculiarities of birds, the different regions of the body have received
names by which intelligible reference can be made to any portion. It
is, perhaps, hardly necessary to say that all living birds have a head
supported on a neck, with jaws extended into a bill covered with a
horny sheath, or with skin, the two jaws situated one above the other,
and always destitute of teeth. The anterior pair of limbs is developed
into wings which, however, are not always capable of use in flight; the
posterior serve as legs for the support of the body in an oblique or
nearly erect position. The body is covered with feathers of variable
structure and character, both in the young bird and the old. (The wings
are apparently wanting in some fossil species.)
The following terms, English and Latin, are those most generally
employed in describing the external form of birds, and are principally
as defined by Illiger. In cases where there is no suitable English word
in use, the Latin equivalent only is given. The figure selected for
illustration, drawn by Mr. R. Ridgway, is that of the common American
robin (_Turdus migratorius_, L.), and will be familiar to most students
of ornithology.
A. Body in General (_Corpus_).
1. =Feathers= (_Plumæ_). A dry elastic object, with a central stem at
one end forming a hollow horny tube implanted in the skin at its tip,
the other feathered on opposite sides.
2. =Quills= (_Pennæ_). The large stiff feathers implanted in the
posterior edge of the wing and in the tail.