BOOK REVIEWS 239
The assumption regarding muscular tone continually recurs in his argument because of the importance he gives to postural tonus in determming the emotion experienced, and is essential in the theories he puts forward with regard to repression; but it is of doubtful validity. A few nerve fibres in voluntary muscle are non-medullated. Some of these are branches of medullated nerve fibres, but some are undoubt- edly from the sympathetic. The balance of evidence seems in favour of a few 01 these fibres ending beneath the sarcolemma of the muscle- fibres, while others supply the blood-vessels. But there is a complete lack of evidence that the sympathetic has any but the smallest effect on tone. The unilateral cutting of the sympathetic rami to the nerves supplying the tail of a cat results in a just perceptible curve towards the sound side, which disappears in the course of a few weeks' in about the same time diat the passive dilatation of the blood-vessels recovers. Similar results are obtained on cutting the sympathetic rami to the lumbar nerves of the frog— a just perceptible relaxation of the hind limb occurs on this side which recovers in a few weeks.
There is also evidence that decerebrate rigidity, from the study of which most of our knowledge of tone is derived, is usually not at all affected, though sometimes slightly so, on the side from which the sympathetic ganglia have been excised. The severing of the anterior roots to the hind limbs, leaving the sympathetic' connection intact, completely abolishes decerebrate rigidity, if present, or prevents its onset.
Dr. Kempf says, "The explanation, that postural tonus of skeletal musculature is determined by the autonomic component is the only theory so far given that satisfactorily accounts for the effects of fear rage and love upon postural tonus" and so he assumes it. This seems' to us typical of his attitude of mind. A hypothesis would suit his theory and so he assumes its truth. The suggestions of others and the 'might be' are made the foundation of a top-heavy super- structure.
Dr. Kempt agrees that the visceral changes in different emotions appear to be the same. He suggests that they must be different in some- unknown way, or alternatively that the visceral effects in anger and disgust are really due to fear; leaving unattempted the task of dis- covering the visceral postural tonus resulting in these latter emotions. Sherrington's experiments on two dogs in which the spinal cord was severed in the lower cervical region and the vagi and sympathetic trunks cut, would seem to render Dr. Kempfs theory untenable. The sections were Yerified J>ost mortem. The dogs' expression of fear, disgust pleasure and anger were not dulled. The two readily observed visceral effects present in normal dogs of erection of the hairs and change in pulse rate were absent. In spite of these careful experiments, Dr. Kempf
