183 



In the first case we may have the complex of fig. i^zb, which, 

 by a suitable development of its bordering faces, finally obtains 

 the simulative form of a hexagonal crystal (fig. 1420). 



6. The cases of chabazite and phillipsite are very instructive 

 in so far as it illustrates how strongly the tendency of the original 

 lower symmetrical individual to similate a higher symmetry, is 

 exhibited. The triclinic individual in the first case has the latent 

 predisposition in its space-lattice to imitate a trigonal symmetry; 

 but it has also the capacity of simulating a yet higher symmetry, 

 namely that of a hexagonal crystal. Now repeated twinning is made 

 use of, first, to reach the form of a mimetic, pseudo-trigonal 



Pseudo-rhombohedron 

 of six individuals, 

 parallel to 0001 }. 



b. 



Penetration-twin 

 of two pseudo-rhombohedra. 



Fig. 142. Chabazite. 



Final apparent 

 hexagonal individual. 



individual; but this again combines until finally the deceptive 

 form of the higher symmetrical hexagonal individual is reached. 

 Something analogous takes place with phillipsite. 



The result in all such cases is one of the same kind ; the pseudo- 

 symmetrical crystal finally approaches more closely, by repeated 

 combination of individuals of its own species, to the higher symmetry, 

 to which the predisposition is present as a consequence of its special 

 internal structure, and of which the single individual is only a 

 defective morphological representative. 



This strong tendency to strive at higher perfection by aggregation, 

 is one of the most remarkable facts in inorganic matter; it is a 

 "struggle for higher symmetry", by the aid, as it were, of the 

 most primitive form of "cooperation". Just as union into well- 

 governed states gives a greater stability of life-conditions to human 

 creatures, and is the necessary basis for their speedy and regular 

 progress, so the aggregation of lower symmetrical crystals into higher 

 symmetrical complexes, is probably a way of reaching a higher 



