68 4 SCIENCE PROGRESS 



sinking feeling at the epigastrium, indicative of a bio-chemical deficiency in the 

 blood as the result of a lack of food entering the organs of digestion. 



The appetites connected with the preservation of the individual, hunger, 

 thirst, and the desire for fresh air, can therefore be shown to be dependent upon 

 bio-chemical stimuli arousing instinctive medullary sensori-motor mechanisms 

 controlled and supervised by cerebral activities, affective, cognitive, and conative, 

 with increasing variety and refinement as we rise in the animal scale. 



With the appetites depending upon the organic needs is associated the 

 emotion of disgust which is excited by the sense of smell and of taste ; these 

 senses stand like sentinels to the respiratory and alimentary tracts. It is a 

 remarkable thing that nearly all acrid and bitter plants are poisonous, and 

 excite the feeling of disgust and nausea ; likewise do foul odours and noxious 

 gases. The feeling excites the emotive expression of disgust, and the desire to 

 avoid a recurrence of the experience. The emotion of disgust is a powerful 

 instinctive protective feeling, dependent upon a sub-cortical preorganised sensori- 

 motor mechanism, as was shown by the experiments made by Goltz upon his 

 decerebrate dog. This animal, which could never learn to recognise the man 

 who fed it, but invariably growled and bit and resisted when he took it out of his 

 cage to put the food in its mouth, which it then ate, was given meat containing 

 some bitter substance, such as quinine or strychnine, yet could not be induced to 

 swallow it, not even when given no food for some time. A normal dog was given 

 this meat, and, as Goltz says, he looked wistfully at his master as much as to say, 

 " I don't like it, but I'll swallow it to please you." Here the intelligence of the 

 animal controlled the powerful instinctive protective reaction. A number of 

 physiological experiments teach us that there is a preorganised medullary 

 protective mechanism against injury (apart from pain, which may be regarded as 

 a psychical adjunct), which enables an animal to adapt its behaviour in accordance 

 with a previous perceptual experience, how to avoid pain under a like condition, 

 and so protect its body from injury. There is always a conscious judgment 

 of value in the behaviour of an animal based upon the individual experiences of 

 the animal, but may there not be an instinctive unconscious judgment of value 

 structurally organised in the medullary protective reflex sensori-motor nervous 

 mechanism? This proposition seems to be of importance in relation to one 

 subject in dispute between Mr. Shand and Mr. McDougall. Thus the former 

 asserts that there may be a multiplicity of instincts within an emotional system, 

 and there may be an organisation of the same instinct in different emotional 

 systems ; it is upon these grounds that Mr. Shand differentiates the emotional 

 disposition and the instinct. Mr. McDougall will not accept Mr. Shand's 

 views, and affirms that they are erroneous because they proceed from a radically 

 false conception of instinct, for he regards each instinct to be correlated with 

 a specific emotion. Now instinct is essentially dependent upon sensori-motor 

 mechanisms organised by habitual activities for preservation and propagation 

 in the evolution of the species by natural selection. These habitual actions are 

 dependent upon structural organisation in the spinal and medullary centres, and 

 it appears that there is physiological evidence in support of Mr. Shand's view 

 with regard to the emotion of fear giving rise to several instinctive modes of 

 behaviour, and not, as Mr. McDougall says, one mode of behaviour, namely, 

 concealment. 



Sherrington has shown experimentally that a decerebrate cat, kept alive by 

 artificial respiration and suspended in such a way that the limbs hang loose, will 

 instinctively when injured behave in such a manner as to protect itself from injury 



