3 6 THE POPULAR SCIENCE MONTHLY. 



and beliefs ; showing the effect of environment upon mental con- 

 stitution, and in endless ways contributing to the natural history 

 of human endeavor — all this abundant material has been ably 

 canvassed, but needs to be rearranged upon a psychological basis 

 to form the science of Anthropological Psychology. 



It is so obviously impossible within the present limits to con- 

 sider the facts and generalizations of these departments of science, 

 that no justification is necessary for confining our attention to 

 some consideration of the relations of these three paths of de- 

 velopment to one another, and particularly to the psychological 

 position of man. In so doing excursions into each of the fields 

 will be made, and some glimpses be obtained of the several de- 

 partments of Comparative Psychology. 



To appreciate the comparison of infant with animal traits, one 

 must bear in mind some important characteristics differentiating 

 the young of the human kind from the young of other animals. 

 The series of changes of which an individual life consists indicate 

 that the individual enters life in a condition simpler than that 

 which it eventually attains. These changes diminish in extent 

 as we descend the scale of organisms, until in the lowest organ- 

 isms the newly born and the adult are almost indistinguishable. 

 Whether we consider the embryonic preparatory stage of life, or 

 whether we regard as the beginning of existence the entrance to 

 the environment of Nature, and speak of the preparatory stage as 

 that which intervenes between birth and maturity, we shall find 

 it measurably true that in proportion to the complexity of mental 

 development to which the individual may eventually attain will 

 this pre-adult period be lengthened. An aspect of this law, of 

 special psychological interest, is the resulting difference in the 

 powers present in the newly born of different species : the lower 

 organism has a larger share of its powers ready at birth, has less 

 to learn, less to be modified by and adapted to its environment 

 than has the higher organism. Many of the marvelous instincts 

 characteristic of the insect tribe seem to be at the service of the 

 new-born individual. " With such creatures as the codfish, the 

 turtle, or the fly-catcher, there is . . . nothing that can be called 

 infancy " (Fiske). The most complete experiments bearing upon 

 this point are those of Mr. Spalding. In the first minutes of life 

 chickens follow " with their eyes the movements of crawling in- 

 sects, turning their heads with the precision of an old fowl. In 

 from two to fifteen minutes they pecked at some speck or insect, 

 showing not merely an instinctive perception of distance, but an 

 original ability to judge, to measure distance, with something like 

 infallible accuracy." A chicken hooded as it emerged from the 

 shell was unhooded when three days old ; six minutes later " it 



