4 TRANSACTIONS OF THE PLYMOUTH INSTITUTION. 
Such of these actions as must, from the necessity of things, 
have been continually or commonly recurring, seem to have become 
automatic, i.e., proceed from the external stimulus without any 
further consciousness or judgment being used. For instance, 
Terrier (page 35) found that "a fish deprived of the brain main- 
tains its normal equilibrium in the water, and uses its tail and 
fins in swimming with as great precision and co-ordination as 
before. It is, however, continually on the move. Left to itself in 
the water it swims in a straight line, and unlike other fishes, which 
stop to smell or nibble at this or that, it keeps on its course as if 
impelled by an irresistible impulse, and is only stopped by the 
sides of the vessel, or worn out by fatigue." The sensation of the 
water on the skin supplied the stimulus which resulted in the 
continued swimming. 
It will be seen that the question of the unity of consciousness 
is here raised. The fish had lost in its brain the higher conscious 
or judging-power instructed by the various organs of sense, and 
therefore these no longer influenced the spinal cord ; but the 
query remains, whether the spinal cord itself is conscious in its 
co-ordination of the swimming muscles. If merely automatic, 
it is still usually under the power of the higher nervous centres, 
as its actions are modified when in connection with them by their 
particular direction. Another question arising here is, Whether 
the action of the spinal cord, if merely automatic and unconscious, 
was so always 1 or was it initiated in consciousness, and has it, after 
ages of use, passed out of consciousness ? 
The law of reflex action is a very general one, and a great many 
actions which we are perhaps accustomed to regard as voluntary or 
intelligent, are really produced by reflex action on a previously 
prepared nervous connection. Take for instance the act of 
reading. By slow and continual efforts we have established a 
nervous connection between the visual shapes of printed or written 
words, their sound to the ear, their oral utterance, and the usual 
meaning or relation which they have to our every-day actions. 
When we read, our action is almost entirely reflex ; the sight of 
the words excites the corresponding idea or purpose in the senso- 
rium of the brain, which combines and sends out the very com- 
plicated muscular actions which produce the articulate voice. In 
the case of blind people, who can read by feeling with the fingers, 
the probable initiation of the connection may have been by writing. 
