The Expression of Emotion in Man and Animals [41]
With their plumage in this state, they rush at each other with open beaks and threatening gestures. Mr. Weir concludes from his large experience that the erection of the feathers is caused much more by anger than by fear. He gives as an instance a hybrid goldfinch of a most irascible disposition, which when approached too closely by a servant, instantly assumes the appearance of a ball of ruffled feathers. He believes that birds when frightened, as a general rule, closely adpress all their feathers, and their consequently diminished size is often astonishing. As soon as they recover from their fear or surprise, the first thing which they do is to shake out their feathers. The best instances of this adpression of the feathers and apparent shrinking of the body from fear, which Mr. Weir has noticed, has been in the quail and grass-parrakeet.[15] The habit is intelligible in these birds from their being accustomed, when in danger, either to squat on the ground or to sit motionless on a branch, so as to escape detection. Though, with birds, anger may be the chief and commonest cause of the erection of the feathers, it is probable that young cuckoos when looked at in the nest, and a hen with her chickens when approached by a dog, feel at least some terror. Mr. Tegetmeier informs me that with game-cocks, the erection of the feathers on the head has long been recognized in the cock-pit as a sign of cowardice.
The males of some lizards, when fighting together during their courtship, expand their throat pouches or frills, and erect their dorsal crests.[16] But Dr. Gunther does not believe that they can erect their separate spines or scales.
We thus see how generally throughout the two higher vertebrate classes, and with some reptiles, the dermal appendages are erected under the influence of anger and fear. The movement is effected, as we know from Kolliker's interesting discovery, by the contraction of minute, unstriped, involuntary muscles,[17] often called _arrectores pili_, which are attached to the capsules of the separate hairs, feathers, &c. By the contraction of these muscles the hairs can be instantly erected, as we see in a dog, being at the same time drawn a little out of their sockets; they are afterwards quickly depressed. The vast number of these minute muscles over the whole body of a hairy quadruped is astonishing. The erection of the hair is, however, aided in some cases, as with that on the head of a man, by the striped and voluntary muscles of the underlying _panniculus carnosus_. It is by the action of these latter muscles, that the hedgehog erects its spines. It appears, also, from the researches of Leydig[18] and others, that striped fibres extend from the panniculus to some of the larger hairs, such as the vibrissae of certain quadrupeds. The _arrectores pili_ contract not only under the above emotions, but from the application of cold to the surface. I remember that my mules and dogs, brought from a lower and warmer country, after spending a night on the bleak Cordillera, had the hair all over their bodies as erect as under the greatest terror. We see the same action in our own _goose-skin_ during the chill before a fever-fit. Mr. Lister has also found,[19] that tickling a neighbouring part of the skin causes the erection and protrusion of the hairs.
[15] _Melopsittacus undulatus_. See an account of its habits by Gould, `Handbook of Birds of Australia,' 1865, vol. ii. p. 82.
[16] See, for instance, the account which I have given (`Descent of Man,' vol. ii. p. 32) of an Anolis and Draco.
[17] These muscles are described in his well-known works. I am greatly indebted to this distinguished observer for having given me in a letter information on this same subject.
From these facts it is manifest that the erection of the dermal appendages is a reflex action, independent of the will; and this action must be looked at, when, occurring under the influence of anger or fear, not as a power acquired for the sake of some advantage, but as an incidental result, at least to a large extent,
The males of some lizards, when fighting together during their courtship, expand their throat pouches or frills, and erect their dorsal crests.[16] But Dr. Gunther does not believe that they can erect their separate spines or scales.
We thus see how generally throughout the two higher vertebrate classes, and with some reptiles, the dermal appendages are erected under the influence of anger and fear. The movement is effected, as we know from Kolliker's interesting discovery, by the contraction of minute, unstriped, involuntary muscles,[17] often called _arrectores pili_, which are attached to the capsules of the separate hairs, feathers, &c. By the contraction of these muscles the hairs can be instantly erected, as we see in a dog, being at the same time drawn a little out of their sockets; they are afterwards quickly depressed. The vast number of these minute muscles over the whole body of a hairy quadruped is astonishing. The erection of the hair is, however, aided in some cases, as with that on the head of a man, by the striped and voluntary muscles of the underlying _panniculus carnosus_. It is by the action of these latter muscles, that the hedgehog erects its spines. It appears, also, from the researches of Leydig[18] and others, that striped fibres extend from the panniculus to some of the larger hairs, such as the vibrissae of certain quadrupeds. The _arrectores pili_ contract not only under the above emotions, but from the application of cold to the surface. I remember that my mules and dogs, brought from a lower and warmer country, after spending a night on the bleak Cordillera, had the hair all over their bodies as erect as under the greatest terror. We see the same action in our own _goose-skin_ during the chill before a fever-fit. Mr. Lister has also found,[19] that tickling a neighbouring part of the skin causes the erection and protrusion of the hairs.
[15] _Melopsittacus undulatus_. See an account of its habits by Gould, `Handbook of Birds of Australia,' 1865, vol. ii. p. 82.
[16] See, for instance, the account which I have given (`Descent of Man,' vol. ii. p. 32) of an Anolis and Draco.
[17] These muscles are described in his well-known works. I am greatly indebted to this distinguished observer for having given me in a letter information on this same subject.
From these facts it is manifest that the erection of the dermal appendages is a reflex action, independent of the will; and this action must be looked at, when, occurring under the influence of anger or fear, not as a power acquired for the sake of some advantage, but as an incidental result, at least to a large extent,