ft> 



56 



contrast existed in the evolutionary development of living and of 

 so-called inanimate matter. For in the domain of crystallography 

 generally the holohedral classes of each system show an incom- 

 parably greater number of representatives than the hemihedral and 

 tetartohedral classes, and it was therefore suggested by some 

 crystallographers, that hemihedral development might only be a 

 result of particular circumstances during the growth of the crystal, 

 a view which can, however, hardly be thought justified. As we shall 



see later, crystals have in many 



jjjV /||\ ^$^L cases a ^ so a tendency to syn- 



crystallise in apparently higher 

 symmetrical aggregations than 

 they are themselves, and thus 

 often imitate a symmetry of 

 the composed individual ob- 

 tained by polysynthetic twin- 

 ning, much higher than their 

 own. 



In living nature on the other 

 hand, it seems that the mor- 

 phological evolution goes in the 

 direction from higher to lower 

 Fl 'g- 58 - symmetry 1 ). 



a. Galeopsis dubia. b. Lamium P ur P u>eum. 

 c. Brunella grandiflova. d. Paphiopedilum 

 Hookerae. e. Dalhousiea bracteata. /. Cy- 



dopia genistoides. g. Podalyna cordata. frequent occurrence of the bila- 



teral symmetry among higher 



animals has not yet been explained in a rational way. Although, 

 therefore, the deeper causes of this phenomenon are not yet known, 

 there are reasons to suspect, that they are in some way connected 

 with the particular circumstance of "animal motion". Among the 

 lower beings there are many, of which a sedentary life is characte- 

 ristic; and it may for the living being be of advantage for the 

 purpose of nutrition, etc., to be in contact with its environment in as 

 many directions as is possible. Evidently the symmetrical repetition of 

 parts or organs of its body is a way of accomplishing this. In general 

 the immobility of the living organism is a factor much more compa- 



wise: in any case the fact of the 



*) Cf. also: G. Bohn, "La naissance de V intelligence" , Paris, Ed. E. Flamma- 

 rion, (1917), pag. 113138. 



