THE ARROW-HEAD. 79 



help to conceal them from their prey in the various situations 

 where they live and hunt, and so in " the survival of the fittest " 

 these advantages have been developed. I sometimes wonder if it 

 ever occurred to any of them to inquire what, on this or any other 

 grounds, is the reason for the infinite variety in the form, size, 

 appearance and structure of the leaves of plants. Has it come 

 about from some early advantage which attended a given form in 

 a given situation. Or has it been developed as the necessary result 

 of some corresponding peculiarity in the structure of the plant ? 

 Or is it a caprice, or blind force? Or shall we say that the Mind 

 in nature is artistic and demands beauty as well as use? The 

 aspen leaf trembles with the greatest agitation when touched with 

 the gentlest zephyr's breath. But there is a physical, not a senti- 

 mental or aesthetic, cause for that. The leaf-stalk is flattened 

 thin in a direction perpendicular to the plane of the leaf, so that 

 the slightest movement of the air will set it into these unsteady 

 oscillations. Do all the facts of nature have thus only a phys- 

 ical cause back of them? They probably have that. But that 

 there is nothing beyond the physical reason I am not prepared to 

 believe. 



The better demonstration of the presence of Mind in nature 

 which is found in a study of the position of the leaves upon 

 the plants must be deferred to another occasion. 



The Sagittaria grows with its feet in the " still waters " by the 

 edges of pools and sluggish streams, a near friend and neighbor of 

 the water-lily. It blooms all summer, and is very common. Some- 

 how this interesting plant is associated in my memory with such 

 summer scenes and such a sunny atmosphere as the poet has 

 painted in these exquisite lines. 



