ADAPTATION IN CRYSTALS. 337 
it is determined by this inner original formative tendency, 
is the result of the specific and definite way in which the 
smallest particles of the crystallizing matter unite together 
in different directions according to law. That independent 
inner formative force, which is directly inherent in the 
matter itself, is directly counteracted by a second formative 
force. The external constructive force, or the external 
formative tendency, may be called Adaptation in crystals as 
well as in organisms. Every crystal individual during its 
formation, like every organic individual, must submit and 
adapt itself to the surrounding influences and conditions 
of existence of the outer world. In fact, the form and size of 
every crystal is dependent upon its whole surroundings, for 
example, upon the vessel in which the crystallization takes 
place, upon the temperature and the pressure of the air 
under which the crystal is formed, upon the presence or 
absence of heterogeneous bodies, etc. Consequently, the 
form of every single crystal, like the form of every single 
organism, is the result of the interaction of two opposing 
factors—the inner formative tendency, which is determined 
by the chemical constitution of the matter itself, and of the 
external formative tendency, which is dependent upon the 
influence of swrrownding matter. Both these constructive 
forces interact similarly also in the organism, and, just as in 
the crystal, are of a purely mechanical nature and directly 
inherent in the substance of the body. If we designate the 
growth and the formation of organisms as a process of life, we 
may with equal reason apply the same term to the developing 
crystal. The teleological conception of nature, which looks 
upon organisms as machines of creation arranged for a 
definite purpose, must logically acknowledge the same also 
VOL, I. Zz 
