MUSCLE AND MIND. 377 



MUSCLE AND MIND. 



By FBANCES EMILY WHITE, M. D. 



THE fundamental characteristic of the animal world, as dis- 

 tinguished from the vegetable world, lies in its different 

 relations to the energies of matter. Every animal is a mechanism 

 for the liberation of energy previously stored up, in great part, in 

 the tissues of plants which serve as food for these higher forms of 

 life ; and the quantity and kinds of energy liberated in any ani- 

 mal are determined mainly by the degree of development of the 

 muscular and nervous systems, the other tissues and organs of the 

 body being subservient to these two, which have been well styled 

 the master tissues. 



But the animal differs from the plant, not only in the power 

 of liberating energy, and thus acting on the outside world ; it is 

 also differently affected by the outside world, the energies of 

 which play upon its living tissues as the wind upon the strings 

 of an JEolian harp ; and the sensitive organism thrills under these 

 influences with responsive sensations of greater or less diversity 

 and intensity according to the variety and grade of development 

 of its sensitive organs. 



The muscular and the nervous tissues, upon which depend the 

 distinctively animal functions of sensation and spontaneous move- 

 ment, develop together, and their relations, both anatomical and 

 physiological, are of the most intimate character. 



Rudimentary nerve - threads are found in the Hydra; first 

 recognized by Klinenberg, they were regarded by him as partly 

 nervous and partly muscular ; and the most primitive fibers posi- 

 tively identified as true nerves serve as pathways of communica- 

 tion from the sensitive surface to the rudimentary nerve-centers, 

 and from these centers to the equally rudimentary muscles of the 

 simple animals to which they belong. In short, the primitive 

 nervous system is merely an immature apparatus for the produc- 

 tion of sensations and the excitation of movements of the kind 

 called " reflex," since they are excited by a stimulus transmitted 

 from the surface of the body to the nerve-centers and thence 

 reflected, as it were, to the muscles ; * and a large proportion of 

 the nerve-bundles which, with the centers, make up the nervous 

 system of man, consists of fibers of communication between the 

 muscles of the trunk and limbs and their stimulating centers in 



* The term " reflex " is a misnomer, as the action of the nerve-center is not the mere 

 reflection of an impulse received from the periphery. The word is used to indicate that 

 the exciting cause of activity of the center arises outside itself, and not, as in so-called 

 " automatic " action, within itself. 

 vol. xxxv. — 24 



