NERVE REFLEXES IN ANIMALS 265 



and throw off waste products are themselves essentially rhythmic in character. They are give-and-take movements 

 in opposite directions, and are comparable to the rhythms of the compartments of the heart, which enable that organ 

 alternately to open and receive blood, and to close and eject it. They are also comparable to all movements 

 occurring in opposite directions, such as the closing and opening of the eyelids, the closing and ojiening of the 

 chest, the several parts of the aUmentary canal, bladder, and so on. 



Plants and animals, in virtue of their vital powers, can take in, retain, and eject at discretion the elements on 

 which they Uve. They can also recognise and take stock of their surroundings ; in other words, they can appreciate 

 the matter in their vicinity which forms their environment. This being so, it follows, that certain changes and 

 movements, as between plants and animals on the one hand, and the elements and all parts of the physical universe 

 on the other, must take place. It follows, further, that the changes and movements must, fundamentally, be atomic 

 and molecular in character, and capable of manifesting themselves in all kinds of hving substances and tissues, as 

 apart from nerves and muscles, which are mere differentiations. If rhythms and reflexes find their highest expression 

 in nerves and muscles, it must never be forgotten that they do not originate in either, and are traceable to lowly 

 organisms and structures, and even to plant and animal protoplasm. 



This is a matter of very considerable importance, because, according to existing views, the highest animals are 

 too sharply defined and too widely separated from the lower animals. The distinctions between plants and animals 

 are also exaggerated. All plants and animals are endowed by nature with movements of some kind. They are 

 also endowed with the power of acting upon the elements which enter into their composition and by which they are 

 surrounded. The movements and powers referred to are necessary to their existence and well-being. If plants 

 and animals cannot absorb, assimilate, retain, transmit, and discharge matter, they languish, pine, and die. In 

 order to hve they must be endowed with the power of taking in or receiving, of assimilating and retaining, and 

 of extruding and casting off effete matter. They must be superior to the matter amongst which they are placed. 

 To this there is no exception. This remark applies equally to the plant and animal ; to alimentation, respiration, 

 the circulation of nutritious juices, the extrusion of effete matter, &c. As is well known, the rhythms and reflexes 

 in the higher animals are dominant factors in the respiratory movements of the chest and lungs, in the vermicular 

 movements of the aUmentary canal, bladder, and uterus, and in the movements of the several compartments of the 

 heart. They are primarily concerned with the incorporation of matter in the form of air, drink, food, offspring, &c. 

 They are secondarily concerned in the recognition of matter not to be incorporated ; the recognition, in the higher 

 animals, being effected either by the skin, or the sense organs as the instruments and representatives of the brain. 

 The skin and sense organs are specially modified and differentiated for this purpose. The cells and tissues com- 

 posing them are equal to dealing with many kinds of matter and many kinds of motion — with objects touched, 

 with the quaHties thereof, as roughness, smoothness, &c., with tasting and smelling bodies, -with vibrations of 

 various kinds, with the undulations of fight and sound, with substances near and remote, with matter in a gaseous, 

 fluid, semi-fluid, and sofid form — with, in short, nearly everything in the physical universe. The higher the animal, 

 and the greater the degree of differentiation and division of labour, the greater the power of recognition. It is 

 his superior powers of recognition which places man on a pedestal by himself, and makes him \-irtually the ruler 

 of the world. 



The differentiation and speciaUsation in the nervous system is proved by the fact that if the optic nerve be 

 divided and the cut end next the brain artificially excited, luminous flashes and the feehng of fight are produced 

 in the brain itself. If, again, a motor nerve be divided and the cut end next the muscle stimtdated, the muscle to 

 which the nerve is distributed is set in motion. Similar remarks are to be made of the sensory nerves. If, for 

 example, in cases of amputation of the hands and feet, the peripheral ends of the cut sensory nerves become 

 diseased, the patients complain of uneasiness and pain in the fingers or toes of the amputated parts. The nervous 

 system, when intact, feels at every point and moves at every point, and this with or without a brain. It is self- 

 acting in the sense that it originates and sends out motor impulses as well as receives sensory impressions. An 

 animal with a brain, sense organs, and sensory and motor nerves, immediately and directly feels everything it touches. 

 It is the prerogative of the brain to feel to the finger tips and to move to the finger tips. The animal feels through- 

 out its entire cutaneous and mucous surfaces, and moves in all its parts by means of its muscles, voluntary and 

 involuntary. It is the brain which primarily feels and moves in the higher animals ; feeUng extending to the 

 extremities of the sensory nerves and motion to the extremities of the motor nerves. 



The brain and nervous system require no intermediaries for their operations, other than the sensory and 

 motor nerves and the sense organs. Their fundamental function is to feel and move, and this they can do at first 

 hand, as apart from artificial stimulation and irritation. 



When an animal elects to feel, it advances part of its body, so as, if possible, to come in contact with the object 

 to be recognised. The eye, so to speak, projects itself into space and searches for things near and remote ; the ear 

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