THE SPECIAL SENSES. 



ACCORDING to the now almost universally (that is, among educated scien- 

 tific people) accepted theory of Evolution, each living being upon this 

 earth is a result of a very slow process of development, which com- 

 menced with a low form of life many millions of years ago, and has since 

 been operating continuously, becoming more and more complex, and 

 imperceptibly attaining greater perfection as each fresh stage was accom- 

 plished. From the homogeneous to the heterogeneous, from inorganic 

 to organic, from Amoeba to man, the evolutionary development has 

 slowly, steadily, and surely advanced step by step, in obedience to cer- 

 tain well-defined laws. Yet it is impossible to discern in this slow 

 process of evolution any well-marked difference between one particular 

 species and the next of kin, although the difference becomes clearly ap- 

 parent if we take two species separated from each other by considerable 

 time ; just as it is impossible to detect any alteration in form and feature 

 between a child of six days old and the same child of seven days old, 

 while the change is very evident after the lapse of several weeks or 

 months. If we were to photograph a human being regularly each day 

 from the moment of its' birth to the time of its decease at the age of 

 eighty, we should be unable to detect any real difference between the por- 

 traits on any two consecutive days ; but the difference between the child 

 of a week old and the young man of twenty years would be enormous, 

 as would be that between the full-grown youth and the tottering old 

 man. As the human individual in its earliest condition of existence is 

 not possessed of the same faculties as it afterwards enjoys as a more per- 

 fect development, so, in like manner, the species in its primal condition 

 was wanting in the loftier qualities now possessed by the higher animals, 

 such as consciousness, sight, hearing, taste, smell, and touch, all of 

 which have been gradually evolved as the various life-forms developed 

 from lower and more simple to higher and more complex kind. For 

 instance, at a very early period of man's individual existence he pos- 

 sessed no brain, eyes, ears, mouth, or nose, and, therefore, was quite in- 

 capable of mentating, seeing, hearing, tasting, or smelling ; but, as the 

 organism very gradually developed into a higher and more - complex 

 kind, these various organs manifested themselves, and slowly arrived at 



