RESULT OF BEAUTIFUL PROPORTIONS. 415 



traction ; aud as, on the other hand, the Avork of depurating the muscular system 

 devolves upon the circulatoiy apparatus, the economy must be provided with the 

 special organs through which the blood can eliminate with facility the products 

 of tissue-change with which it is burdened. 



These are the organs which Professor Baron ' calls automatic cleansers. By 

 their intervention the living machine is cleared, without its knowledge, of what 

 its functional activity would clog it with. Such are the lungs, the external and 

 internal tegumentary surface, the different cutaneous glands, and the kidneys. 



From what has been said it results that prolonged exercise is 

 always accompanied by an expenditure of food, of blood, and of nerv^e- 

 tissue, by an increased circulation, by an acceleration of respiration, by 

 a rise in temperature, and, finally, by a greater activity of the diifereut 

 emunctory surfaces, principally the sudorific glands and the kidneys. 



Cessation of Locomotory Activity. — Tiie above principle 

 being admitted, it is plain that the cessation of locomotory activity will 

 be due to the indirect influence of one of the two following causes : 

 the animal will stop either from nervous exhaustion or from an ex- 

 cessive accumulation of waste products in the muscles (as was said 

 above, by the dogging of his muscles). 



Nervous exhaustion evidently varies according to the quality and 

 the abundance of force-accumulation t)f the cerebro-spinal system and 

 the way in which the nervous force is expended. All subjects, as we 

 know, are not equally gifted in this respect; but, as to equality of 

 blood, it is certain that the more the contraction is sudden, intense, 

 prolonged, and repeated, the more will the exciting principle of the 

 organism diminish and the quicker will it reach its last limit. As 

 to muscular accumulation of waste products, it is caused by the in- 

 sufficiency of the emunctories, the circulatory, respiratory, urinary, and 

 sudorific apparatus. Sometimes the blood does not carry away the 

 excretions as rapidly as they are formed ; sometimes it is not fhor- 

 oughly purified in the lungs, the kidneys, the sudorific glands ; some- 

 times, finally, it is not rich enough in primary constituents. Then 

 one of two things will occur : either it returns to the muscle still 

 loaded with waste materials, — that is to say, with products which 

 cause the latter to lose its contractility, — or it reaches it not properly 

 provided with the substances (oxygen and other muscular aliments) 

 without which this quality cannot be put into action. In each of 

 these cases locomotory activity is diminished and prevented, even by 

 the fact of the functional unfitness of the organs whose co-operation 

 it necessarily requires. 



> R. Baron, La Dynamom6trie biologique, in Archives vetSrinaires, annee 1877, t. ii. p. 754. 



