NERVO-MUSCULAR EXPRESSION. 585 



and actual condition of the working of his brain. The educated and 

 refined singer trains and refines his whole mind, i. e., his brain, and is 

 well aware that his " whole soul," as he may express it, comes out in 

 the action of the muscles concerned in producing his song and musical 

 notes. In the infant the condition of the nervous system is best re- 

 corded in terms of nerve-muscular phenomena. It laughs, and is play- 

 ful ; reflex action is well marked when a finger is placed in the child's 

 mouth. The eyes are moved and directed toward any object looked 

 at ; these are conditions of healthy action. It is well known that in 

 the convulsive state the fists are often closed, with the thumbs turned 

 in. All these examples of expression are nerve-muscular conditions ; 

 the movement, the attitude, the gait, result from states of the brain or 

 spinal cord. 



The normal movements of the eye are seen in the varying condi- 

 tions of the pupil under the influence of light, in the changes accom- 

 panying accommodation for near and distant vision, and in the turning 

 of the eyes in any given direction, a movement in which the parallelism 

 of the axes of the organs is usually maintained. Each of these move- 

 ments is supposed to be governed by a particular brain-center ; and 

 the convergence of the lines of the axis which takes place when the 

 eyes are called upon to look at some very near object involves a com- 

 plicated association of muscular conditions. The associated move- 

 ments of the eyes may be completely lost in deep anaesthesia from 

 chloroform, in coma from alcoholism, or in the profound sleep of in- 

 fants. If, in an adult deeply under the influence of chloroform, the 

 eyelids be gently raised, the pupils will be seen minutely contracted, 

 often to a pin-point, the eyes having at the same time lost the paral- 

 lelism of their axes. One eye may move upward or outward, while 

 the other remains quiet, or moves in a different direction or at a dif- 

 ferent pace, thus causing a temporary and varying strabismus. Usu- 

 ally these movements are confined to the horizontal plane ; less com- 

 monly the eyes assume a different level, one being in the horizontal 

 plane while the other is turned downward. In these cases the co- 

 ordination of the movements is restored with returning consciousness. 



Loss of associated movements may sometimes be easily detected 

 in very weakly infants while awake and sucking at the bottle, and in 

 cases of meningitis and other conditions of coarse brain-disease ; and 

 sometimes appears to be chronic in paralyzed or partly paralyzed and 

 idiotic persons. Many of the lower animals have the power of moving 

 either eye separately and independently, a fact which leads to the sug- 

 gestion that the brain-center that co-ordinates the movements of the 

 two eyes may be looked upon as one more recently developed in the 

 ascent of man. 



In nystagmus, a disease in which the eyeballs oscillate rapidly, usu- 

 ally in an horizontal, rarely in a vertical direction, the parallelism of the 

 axes is generally maintained. In one recorded case, the eyes were capa- 



