Why a Cat Arches Its Back.

New Zealand Graphic, Volume XXXVIII, Issue 21, 25 May 1907, Page 40

Why a Cat Arches Its Back.

Nature has taught tlie cat how to make up for small size and weakness by pltiek and nimbleness. In the presence of a dangerous animal the cat arches her back and erects her tail. This increases her apparent size, nwi is calculated to strike terror into the heart of the enemy. It is curious that the eat assumes nearly ihe same attitude when she comes into the room, or sees the family enter. Now’, her object is to attract attention, and with this end iu view she rubs herself against your legs or your chair and puns. The similarity of the attitude assumed under sneli extremely different cireumstaners is explained by 'supposing that apparent increase of size is useful,

either to inspire terror or to sttraat friendly notice.

The eat lias a beauty which, comes of perfect adaptation to a life of emergencies. She is light, swift, quick to perceive, quick to act- She is most at boinv on trees, where her barbarian ancestors looked for their prey. The stealthy and self-effacing movement by which a cat in pursuit of a bird creeps along a bough reminds one of a treesnake. The peculiar iris of a cat’s eye can change the pupil from a vertical slit to a circle, and is excellently suited to an animal which has to pass continually from the shade of dense foliage into full sunlight, and back again into shade. The presence of mind of ihe cat is marvellous. A cat was cliased by two dogs into a corner of the yard with high walls, but the cat escaped unharmed by a gymnastic feat which involved running for several feet up a vertical wall, turning in the air, alighting on the back of one of the dogs, and springing thence U> the top of a gate. One of tlie greatest wonders of the eat is her way of always alighting on her -feet after an accidental tumble. The mechanics of this marvel have puzzled many wise men. While pussy is falling she brings the feet round toward the ground, first the fore feet and then the hind feet. This is accomplished by the twisting of tlie body. In order to twist, one end of the body must be fixed, or at least retarded in its rotation. When suddenly let go, the eat gathers up her fore legs, presses them against her neck, and as near as possible to the axis of the body. In this position tlie moment of their inertia is- a minimum, that is,

they are as free as possible to rotate But the hind legs are extended so as to

make their moment of Inertia a maximum, that is, to oppose the strongest possible resistence to rotation. The hind legs for an instant become a fulcrum, or

relatively fixed point, against which the fore legs can act. Then the fore legs are extended and the hind legs gathered up close to tlie body, when the inertia of the fore legs furnishes the fulcrum for the rotation of the hind legs. The cat can right, herself on her feet in a short spacer One pussy, let go backwards, with only six inches of clear space beneath her, alighted squarely on her feet.