2. As regards the muscles of organic life: arrest of the lacteal secretion, of menstruation, of the salivary secretion; the mouth dry, the tongue adhering to the palate; cold sweats, “goose-flesh,” bristling of the hair, arrest of respiration, oppression, constriction of the throat. Fear also, as is well known, influences the intestinal secretions. 3. As regards the vaso-motor apparatus: a spasmodic constriction of the vessels, shiverings, violent spasm of the heart; and if the impression is of excessive violence, paralysis, which may end in death; pallor, and peripheral anæmia. These manifestations collectively express a lowering of the vital tone which in no other emotion is so complete and so clearly marked. It has been maintained with reason that fear has a teleological character, that it is adapted to an end—that of withdrawing, escaping, exposing one’s self as little as possible to attack, and remaining on the defensive in view of possible approaching evil. However, the case is not so simple as it appears. The slight or moderate forms of fear, through the feeling of weakness produced by them in the consciousness, are a protection against hurtful actions by inducing withdrawal or flight. But the grave forms, such as terror and fright, accompanied by trembling and motor annihilation, place us face to face with a great difficulty. When existence is menaced, at the most decisive moment, when attack, defence, or flight is urgently demanded, we see men and animals, paralysed with agitation, fall victims, unable to make any use of what strength they have. Darwin confines himself to remarking that the problem is very obscure (ch. xiii.). Mantegazza (_op. cit._, ch. vii.) alleges that trembling is extremely useful, because it tends to produce heat and warm the blood, which, under the influence of terror, would soon grow cold. Mosso has very good reasons to oppose to his compatriot’s thesis. He considers the “cataplexy” which accompanies the extreme forms of fear as a grave imperfection of the organism. “One would think that nature, in making the brain and spinal cord, was unable to devise a substance of extreme excitability which should at the same time, under the influence of exceptionally strong stimuli, be capable of never passing in its reactions beyond the limits needful for the preservation of the animal.” In short, terror and fright appear to him in the light of morbid phenomena. From the naturalistic point of view this extra-teleological position is perfectly admissible. A finalist conception of the world admits of no exceptions, and has to explain everything according to its own principle; but if we content ourselves with saying that the conditions of existence of a living being are sometimes given, sometimes absent, we have no more to do but verify the cases in which they are wanting and the occurrences logically following therefrom.