(c) The neck.—In the feathered bird this appears short; it will be better seen after the removal of the feathers (contour feathers) which cover it. (d) The trunk.—What is the apparent shape of the trunk? Where is its heaviest part? (e) The wings.—Open out the wings fully and measure the distance from tip to tip; compare it with the length of the trunk. Which surface, upper or lower, of the expanded wing is rounded (convex) and which is hollowed (concave)? Put up an umbrella and, holding it by the handle, move it quickly (i) away from you, (ii) towards you. In which direction of motion does the air offer more resistance? Is it an advantage for the expanded wing to be convex above and concave below? Why? Feel the wing-bones through the skin, and notice that the wing-skeleton consists of three parts corresponding to the bones of your upper-arm, fore-arm, and hand (with the wrist) respectively; and that they are bent on each other in the form of a Z when the wings are folded. The large quill-feathers attached to the segment which corresponds to the hand and wrist are called primaries; count them. Those attached to the fore-arm are called secondaries; count them. Find the tuft of smaller feathers which spring, at the front edge of the wing, from the thumb; this tuft is called the thumb-wing. The primaries and secondaries collectively may be called the rowing feathers. Notice the smaller feathers which, on both the upper and lower surface of the wing, cover the quills of the primaries and secondaries; these smaller feathers are called the wing-coverts. (f) The legs.—Feel the leg-bones through the skin, and make out the various segments. Is the whole of the hind-limb feathered? Which part is devoid of feathers? With what is this part covered? How many [Pg 267] toes are there? Do any point backwards? Stretch out the legs and notice that the toes open. Bend the ankle-joint and notice that the toes close automatically. Of what use is this in perching? (g) The tail.—Examine the tail and notice the large quill-feathers attached to it; count them. As they are largely used for steering during flight they are sometimes called the steering feathers.