Pack Two 



EVOLUTION 



The Maze of Species 



By Hensiiaw Ward 



March, 1928 



THERE is one simple reason why a non-scientist may 

 find it hard to believe the evolution theory: he 

 knows nothing about the infinite number of variations 

 within the species of plants and animals. He supposes 

 that a "species" of animal is a fixed, clean-cut depart- 

 ment of life which can always be identified; he sup- 

 poses that the difference between an animal and a plant 

 is a definite and impassable barrier; he supposes that a 

 "species" of plant is a peculiar sort of organism which 

 a botanist can always recognize. 



But the truth is just the opposite: it is difficult to draw 

 a dividing line between plants and animals; most spe- 

 cies have variant forms that link them with other spe- 

 cies; within every widely-distributed species there are 

 endless variations. The biologist has to believe in evo- 

 lution because he finds that every flourishing family of 

 organisms is a maze of interlaced forms which would 

 be a disorderly nightmare if it were not for an evolu- 

 tion tlieory. 



I will present some illustrations from botany.* 



How many kinds of mosses have you ever heard of? 

 If we had never seen but ten kinds, we could rest with 

 the supposition that they were originally created so; 

 but when we learn that there are sixteen thousand spe- 

 cies of these inconspicuous growths and that the more 

 common of the species have varieties that grade off in- 

 sensibly into varieties of other species, then we can not 

 be content with any such guess at the cause. The more 

 a botanist becomes familiar with the countless varieties 

 of plants, the more certain he feels that he is dealing with 

 some sort of continuous growth of the whole system of 

 organisms. A few dozen different ferns would never 

 have excited a Wallace or a Darwin to cudgel his brains 

 for an interpretation of nature: but the four thousand 

 five hundred species that botanists now know might well 

 cause an inquisitive mind to lie awake at night. 



There are about one hundred thousand species of this 

 lower division of plants. Of the higher division, the 

 flowering plants, there are more than one hundred and 

 thirty thousand species. Some of the items that make up 

 the total are five thousand grasses, one thousand palms, 

 two thousand lillies. seven thousand orchids, one thou- 

 sand two hundred cactuses. 



More significant than mere numbers is the way in 

 which plants unlike in appearance are found to be alike 

 in their anatomy and way of growing, so that kinds which 

 are very dissimilar in all outward appearance are found 

 to have inwardly a decided family resemblance. Thus 

 elm trees, fig trees, nettles and hops are found to have 

 such similarity in their flowers that they belong together. 

 The figs include such apparently unlike plants as the 

 rubber tree, the banyan and a vine-like parasite. In an- 



* Taken from Evolution for John Doe, Pages 24-26. 



other great group the botanists have been obliged to lump 

 together geraniums, flax, oranges, mahogany and castor 

 beans, because they are similar in their ways of propa- 

 gating. The scientists have no desire to do queer things; 

 they would much prefer to say that rubber trees and 

 milk- weeds are alike because of their milky sap; simpli- 

 city has always been their aim. But nature has made it 

 impossible for them to find any simple way of classifying. 

 It is as if she had strung the most diverse forms on one 

 thread of structure, and had then so looped and tangled 

 the thread that the botanists are taxed to their wits' ends 

 to straighten it out in anything like orderly sequence. 

 Wlien a man has labored for thirty years at this effort 

 to untangle related forms, he comes to think of plant 

 life as a labyrinth, and he demands a clue. What will 

 guide him? His work would be easier if he could dis- 

 cover that all the crisscrossing forms were originally 

 created as distinct kinds of organisms, but the opposite 

 conviction is continually thrust upon him — namely, that 

 all plant life has forever been altering in character, put- 

 ting out changes here, there and everywhere. 



The puzzle would not amount to much if a species were 

 always a species — if, for example, a certain kind of pine 

 tree were everywhere the same. But within any species 

 there may be endless variations, some of them amounting 

 to striking differences. 



An illustration is a certain small grass growing com- 

 monly in the United States and Europe, Draha verna. 

 When samples of this are gathered from different parts 

 of the world, it is found that there are many distinct 

 types — no less than two hundred have been counted, each 

 of which will breed true from seed. Each of these types, 

 the so-called "varieties", might be called a species. Any 

 naturalist who cares to cultivate the varieties can breed 

 new ones; he can, as it were, watch the plant branching 

 out into new forms. A botanist in Amsterdam once 

 counted seven hundred varieties of hyacinths. It is esti- 

 mated that American florists have caused fifty species of 

 irises to branch out into one thousand five hundred dis- 

 tinct varieties, that they have developed as many forms 

 of roses, and that there have been produced in the gar- 

 dens of the world no less than eight thousand varieties 

 of roses. The great Dutch botanist De Vries says of 

 hawkweed : 



"Thousands of forms may be cultivated side by side 

 in botanical gardens, exhibiting undoubted differentiat- 

 ing features, and reproducing themselves truly by seed." 



What shall a naturalist conclude after he has spent 

 studious decades in watching these ceaseless fluctuations 

 of countless forms of plant life? What shall he think 

 when he takes stock of this medley of life, this un- 

 mapped chaos of contradictions and relationships? He 

 has no chart or compass until he adopts the evolution 

 theory; with it he can always steer a course. 



The earth has her boundaries, but human stupidity 

 has no limits. — Gustave Flaubert. 



Logical consequences are the scare-crows of fools and 

 the beacons of wise men. — Thos. Huxley. 



