THE STRUCTURE AND FUNCTION OF HIGHER PLANTS 65 



as they have in the past. We should always be conscious of our debt to 

 the Flemings, the Floreys, and the Waksmans who labor to make hfe 

 safer and more healthful to their fellow men. 



A TOUR OF A TREE * 



HENSHAW WARD 



I am standing on a lawn in Carpinteria, near the Coast Highway of 

 Southern California. Above me is a Torrey pine that carries its foliage a 

 hundred feet above the base and spreads it on stout, sprangling arms over 

 a diameter as great as its height. Seen from underneath it is a galaxy of eight- 

 inch needles; from a distance it is a delicate cloud of soft gray-green color. 

 Occasionally some one whizzing by in a car remarks, "There's a big 

 tree." For thirty-six years I have known it, watching it grow from sprig to 

 giant, without making any better comment. 



This morning I begin to notice what a pine tree is. Its trunk, almost 

 four feet in diameter, is a notable piece of architecture, for it bears the 

 strain of a wide-stretched load, through the hardest gales. Its branches are 

 contrived for spreading tens of thousands of needles to the sun and air, so 

 that they may make sugar to feed new twigs which will spread new 

 needles.t Underground there are thousands of regiments of rootlets that 

 forage for water and mineral food, which must be transported to the sugar 

 factories. All these industrious armies of roots and leaves are engaged in 

 one common purpose — nourishing the seeds in the cones. Such a purpose 

 can not be carried out by haphazard. What generalship directs these 

 myriad forces in orderly cooperation? 



If you accompany me on a tour of this tree, viewing the sights that any 

 ordinary microscope shows, you will need no help in making your own 

 speculations about the powers which lie beyond vision. 



Squinting through a microscope is hard work; even for a man of long 

 experience it is a tricky task. The only way to go sightseeing comfortably 

 in a tree would be to reduce ourselves to microscopic size, carrying with 

 us a corresponding increase in power of vision. If, for instance, a man 

 nearly six feet tall could reduce himself to one-tenth of his size, his height 

 would be seven inches. In this tree trip he would see a pineneedle as a red- 

 tipped stake taller than himself, three-sided, with sharp corners; he could 

 see that two of the sides are concave and decorated with seven rows of 

 glistening white spots, while the third is convex and has twice as many 

 rows of spots. He would feel of the saw-teeth on the corners and would 



* From Explor'mg the Universe by Henshaw Ward. Copyright 1927. Used by 

 special permission of the pubHshers, The Bobbs-Merrill Company. 



t Mr. Ward does not mean to imply that plants function for a purpose here or 

 elsewhere in this article. — Ed. 



