286 THE EDUCATIONAL CLAIMS OF BOTANY. 



The beginning of growth is a change in tne germ, by 

 which it is separated into unlike parts. One portion becomes 

 different from the rest, or is differentiated from it ; and then it 

 is itself still further changed or differentiated into more unlike 

 parts. In this way, from the diffused uniform mass, various 

 tissues, structures, and organs gradually arise, which, in the 

 course of growth, constantly become more diverse, complex, 

 and heterogeneous. But, accompanying these changes, there is 

 also a tendency to unity. It is by the assimilation of like 

 with like that differences arise. Nourishment is drawn in 

 from without, and then each part attracts to itself the particles 

 that are like itself. Bone material is incorporated with bone, 

 and nerve material with nerve; so that each different part 

 arises from the grouping together of similar constituents. This 

 tendency to unity, by which each part is produced, and by 

 which all the parts are wrought together into a mutually de- 

 pendent whole, is termed integration; and the combined ope- 

 rations by which development is carried on constitute what is 

 now known as Evolution. 



At birth, bodily development has been carried so far that 

 the infant is capable of leading an independent life. Mental 

 growth commences when the little creature begins to be acted 

 upon by external agencies. An already-growing mechanism 

 takes on a new kind of action in new circumstances, and body 

 and mind now grow together. The development of mind de- 

 pends upon certain properties of nervous matter by which it 

 is capable of receiving, retaining, and combining impressions. 

 An organism has been thus prepared, upon which the sur- 

 rounding universe takes effect, and the growth of mind con- 

 sists in the development of an internal consciousness in 

 correspondence to the external order of the world. 



II. HOW THE MIND GKOWS. 



At birth we say the infant knows nothing ; that is, it recog- 

 nizes no thing. Though the senses produce perfect irnpres- 



some readers may be unfamiliar. But more precise thoughts require more 

 precise terms to mark them ; and, as these terms are now established, their 

 use here is admissible as well as advantageous. 



