THE STRUCTURE AND FUNCTION OF HIGHER PLANTS 67 



like pulpy craters. On our left is the perpendicular cliff of one of the nar- 

 row sides of the needle. It is covered with the same sort of palpitating hum- 

 mocks and is plastered with brownish lumps of resin in which are stuck 

 white and brown boulders — things that mortals call "dust grains blown by 

 the wind." The ridge on which we sit, between these two sides, looks as 

 if it has been formed out of gray gelatine that had hardened with a trans- 

 lucent, glistening surface in a maze of mounds and hollo\^'s. Behind us 

 the ridge slopes up sharply to a height of fifty feet. A hundred yards ahead 

 of us is a queer thing. 



As we clamber toward it, bracing our feet in the rough surfaces of the 

 hollows and gripping the knobs on the mounds, we see that we are con- 

 fronting a cone of gleaming gray. It is embedded in a hill fifty feet high 

 and is pointed toward us, elevated at an angle, like a threatening coast- 

 defense cannon, as if it were set to impale anything that rushed against it. 

 If we clamber to its top and look forward, we see another sharp cone, 

 mounted and pointed toward us in the same way. Back of us along all the 

 miles to the tip, at intervals of from two hundred to six hundred feet, 

 stretches a continuous row of similar cones — three hundred of them. They 

 are the spines that a mortal can feel as a slight roughness when he rubs 

 his thumb down the edge of a needle. 



Of course each spine was constructed by a cell. It was formed by proto- 

 plasm that was pushed out to a sharp point and hardened there. It was 

 created by an organism that was born with this special power, an organ- 

 ism which was one of the dozen of kinds provided for, to the last nicety 

 of detail, in the swarming multitude of growths in the embryo of a cluster 

 of pine needles. And this endlessly complex multitude was at first all pro- 

 vided for in one small part of a single cell. And that cell had been born from 

 another which, within its single self, contained provision for all the sorts 

 of cells that were to form wood and cones on a whole branch. And all the 

 provisions for the branch were just part of an earlier cell that became a 

 pine-cone. There can not be any chance or miracle about the birth of a 

 single spine. It had to be exactly provided for in the ancestor of a line of 

 cells. 



Nor could the individual spines be left to grow as they liked. The number 

 and placement of them had to be governed by some precise apparatus, so 

 that they should grow only on the three edges, that there should be about 

 thirty or fort^^ to the inch, and that all of them should point one way. If 

 we ask why they exist, we shall receive no answer but guesses. Perhaps the 

 young trees were once less likely to be eaten if there were spines to rasp 

 the tongue of some Mesozoic herb-eater. Perhaps — but nobody knows. 

 There they grow, exactly as the seeds of this species have ordained that 

 they should grow for unknown million of years. So stable and enduring is 

 the mechanism of heredity in each of its small details. 



Excuse the lecture while you are clinging for dear life to a mountainous 



