THE PSYCHIC DEVELOPMENT OF YOUNG ANIMALS. 49 



All parts of an animal's body owing to nervous or simply protoplasmic connections 

 merely are in relation to each other, and this must constantly be borne in mind if we would 

 understand psychic as well as physical (somatic) phenomena. The nervous centres, how- 

 ever, constitute a sort of head office or series of offices where the various changes of the body 

 are reported, correlated, etc., in all higher animals. In the youngest, though the cerebrum 

 is but indifferentlj- active as yet, the lower nervous centres are constantly receiving impulses 

 coming from peripheral parts, the viscera included, and if these are of an abnormal or dis- 

 turliing character, there result those forms of expression or external representation of 

 the ingoing effiicts, mostly movements which we can correlate with their causes. Hence the 

 young animal expresses its feelings of discomfort as hunger, cold, etc., by movements, some 

 of which result in cries, whining, etc., and experiments as well as the beliaviour of animals 

 liorn without the cereln-um show that the higlier parts of the brain may l)e little concerned. 



The feeling of discomfort from being in an atmosphere that is not warm enough is dif- 

 ferent somewhat from the sensation, likewise disagreeable, of a body too cold being placed 

 against the skin. Etlccts not contincd to the surtaee but modifying the whole of the vital 

 processes result from the former, as it is well known that very young animals cannot exist 

 at all in a temperature below a certain rather high point as compared with that endurable by 

 nuiture animals. 



Nothing is more striking than the etforts the animal makes almost as soon as it is born 

 til jilace itself in an environment of comfort. The importance of this instinct — -just as fun- 

 damental as sucking, etc. — will be evident when one considers that the vital processes cannot 

 continue except under these conditions. It is even more im[iortant than that there should 

 be a supply of food within the lirst few hours. 



Sucking.: — Sucking has been so frequently referred to by writers as an exam|>le of a 

 perfect instinct that I have taken pains to give some details regarding it, and to trace its 

 modifications and final decline. 



It will be observed hj any one who will without prejudice examine the subject that 

 sucking is not perfect at first — that like the lapping of milk, swallowing, etc., but much less 

 so, it is im^iroved by practice and that it is su1)ject to modification with the increasing experi- 

 ence of the animal. It is true the mechanism of sucking, both muscular and nervous, in 

 consequence of countless ancestral experiences, is like perfectly made machinery in good 

 order — it will work on the slightest stimulus — but later this machinery is better oiled, it 

 works better. That there is but imperfect discrimination as to what is sucked is well shown 

 by my diary ; and that the act only continues a certain time, when milk is not obtained, 

 proves that the instinct is fairly perfect. However, as the notes show, the older the puppy 

 the more perfectly does it utilize the sucking mechanism, the less energy does it waste, e.g. 

 the feet are used to much greater advantage in pressing the mammary glands after a couple 

 of weeks than in the first days. 



Does the puppy find the teats shortly after its birth by smell ? I am convinced that 

 it plays no great part in the matter for some days as far as dogs are concerned. After birth 

 they crawl towards the mother's abdomen to get warmth ; they tend to suck almost anj^ 

 fleshy object that comes in their way that is not cold ; they meet the teats which are the 

 objects best adapted to seize and suck ; getting satisfaction, this is continued. Xo donbt 

 later, smell, the tactile sense, still later vision and a whole host of stored experiences guide 

 in this as in other cases in which instinct is essential and most prominent in the result. But 



Sec. IV., 1S94. 7. 



