1883.] 



On the Formation of Ripple-mark. 

 Fig 4. 



27 



Fig. 4 is the palm-tree stage with gentle oscillation, and figs. 5 and 

 6 represent the appearance when the amplitude is greater. 



Fig. 7 exhibits a tree in which the growth is one-sided on account 

 of inequality between the heights of the bounding crests. 



Fig. 7. 



Fig. 8 represents a mushroom and a tree which I have occasionally 

 succeeded in observing simultaneously. 



