LIST OF ILLUSTRATIONS.

The feet of the Deer, Ornithorhynchus, Otter, Frog, and Seal, .
The Red-throated Dragon,

The Flying Lemur,

The Bat,

The Engravings are, with few exceptions, from Photographs Drawings, and Designs by Mr. Charles Berjeau and the Author. Such as are Lot original are duly acknowledged.

FRONTISPIECE.

In the clutch of the enemy--(The Graphic).
The three orders of lever-(Bishop),

suon),

The skeleton of a Deer—(Pander and D'Alton),
Muscular cycle in the act of flexing the arm,

Screws formed by the bones of the wing of the bird, the bones of the anterior extremity of the Elephant, and the cast of the interior of the left ventricle of the heart,

The muscular system of the Horse-(Bagg),

25

34

35

35

36

Chillingham Bull with extremities describing figure-of-8 movements,

37

Horse in the act of trotting,

Double waved tracks described by Man in walking,

Footprints of the Horse in the walk, trot, and gallop--(Gamgee),
Skeleton of the Ostrich-(Dallas),

39

41

43

The positions assumed by the extremities and feet in walking

59

62

65

65

Swimming of the fish according to Borelli,

Świmming of the fish according to the Author,

67

68

The elliptical, looped, and spiral tracks made in swimming,

The several attitudes assumed by the extremities in swimming

81

The feet of the Swan as seen in the open and closed condition,
The foot of the Grebe with swimming membrane—(Dallas),
Double waved track described by the feet of swimming birds,.
The flight of the Flying-fish,

The wing a lever of the third order,

Figure-of-8 vertical track made by the wing in flight,

Do. horizontal track,

96

97

97

98

105

Feathers and cork flying forward,

112

Diagram illustrating how wings obtain their high speed,
Butterfly with large wings,

Beetle with small wings,

125

Partridge with small wings; Heron with large wings,

The wings of the Hawk and Albatross,

The Green Plover with one wing flexed and the other extended,
Blur or impression produced on the eye by the rapidly oscillat-

136, 137 138

ing wing of the insect,

139

Diagram in which the down and up strokes of the wing of the insect are analysed,

Diagrams illustrating the looped and waved tracks described
by the wing of the insect, bat, and bird,
Figures showing the positions assumed by the wing of the bird
during the up and down strokes (side view),
The positions assumed by the wing of the insect as it hastens
to and fro and describes a figure-of-8 track,
The figure-of-8 curves made by the wing of the bird in flexion
and extension,

The long and short axes of the wing,

The waved tracks described by the wing and body of the bird as they alternately rise and fall, .

144

145

141

147 149

157, 163

The positions assumed by the wing of the bird during the
down and up strokes (front view),
Analysis of the movements of the wing,

The kite-like action and waved movements of the wing,
The Centaur Beetle and Water Bug,

The Dragon Fly,

PAGE

158

160, 161

The screws formed by the wing of the insect, bat, and bird, 174, 175, 176 The muscles, elastic ligaments, and feathers of the wing of the bird,

181

Diagrams illustrating the true and false action of the wing,

The sculling action of the wing as seen in the bird,

The artificial wave wing of the Author,