202 CONSCIOUSNESS IN 



pauied by some such states in Cephalopocls and Insects, or 

 even in lower Vertebrate forms. This, indeed, seems 

 highly probable, judging from facts furnished by our own 

 experience. Each one of us, after a little reflection, will 

 recall the fact that many novel impressions or muscular 

 movements, at first associated with a distinct consciousness 

 of their performance, may, when they have been often re- 

 peated and rendered facile by habit, after a time occur with- 

 out arousing any kind of Consciousness. What has taken 

 place, therefore, during our own individual development, 

 probably has been occurring also to a much wider extent 

 during the gradual development of the Nervous System, 

 through the countless generations of animals, w^hich, in 

 past ages of the earth, have gradually been perfecting 

 their relations with the sum total of their surroundings. 



It may thus well happen that impressions which in 

 lower animals are commonly attended by Consciousness, 

 gradually become in other higher animals (connected with 

 them by descent and the bond of kinship) so habitual 

 that they no longer arouse Consciousness. It seems not 

 unlikely that something of the kind may, in the course 

 of long ages and with untold generations of animal 

 forms, have occurred with certain of the most habitual 

 and least varied of Visceral Impressions, and (though 

 to a less extent) with other impressions emanating from 

 contracting Muscles of all kinds. 



For in organisms of greater Sensorial and correspond- 

 ingly increased Mental Activity, whose higher nerve cen- 

 tres, by reason of these activities, become more engross- 

 ingly occupied with vivid extrinsic impressions, those of 

 an habitual character which emanate from muscles or 

 other internal parts would probably less and less engage 

 the animal's Attention or Consciousness. The customary 

 incitative or guiding impressions will still impinge upon 



