144 



LIFE S BEGINNING ON THE EARTH 



Fig. 55. (a). Parallel Striations Produced by the Interaction of 



Two Substances 



1 natural size 

 (b). Leaves of a Cactus Plant with Similar Striations 



The striations in 55 a are produced as described in Fig. 54, with only this 

 difference: of the two interacting substances, one is contained in a jelly 

 in a test tube, and the other is poured on atop of this jelly. The striations 

 are formed automatically in the jelly in consecutive layers thus producing 

 a parallel striation of great regularity and beauty. 



Figure 55 b is inserted here for comparison. It is a photograph of a cac- 

 tus plant which likewise exhibits a parallel striation of great regularity. 

 This striation seems to be the result of similar physical forces which pro- 

 duce the striation in the test tube experiment on the left, even though this 

 experiment is performed only with simple inorganic salts. 



