14 EXPERIMENTAL EVOLUTION AMONGST PLANTS. 



organic forms. It is certainly a wholly unscientific attitude to 

 demand that forms originating by one of nature's methods are 

 species, while similar forms originating by another method are 

 beneath notice. 



If species are not original entities in nature, then it is useless 

 to quarrel over the origination of them by experiment. All we 

 want to know, as a proof of evolution, is whether plants and 

 animals can become profoundly modified under different con- 

 ditions, and if these modifications tend to persist. Every man 

 before me knows, as a matter of common observation and practice, 

 that this is true of plants. He knows that varieties with the most 

 marked features are passing before him like a moving panorama. 

 He knows that nearly every plant, which has been long cultivated, 

 has become so profoundly and irrevocably modified that people 

 are disputing as to what wild species it came from. Consider that 

 we cannot certainly identify the original species of the apple, 

 peach, plum, cherry, orange, lemon, wine grape, sweet potato, 

 Indian corn,, melon, bean, pumpkin, wheat, tobacco, chrysanthe- 

 mum, and nearly or quite a hundred other common cultivated 

 plants. It is immaterial whether they are called species or varieties. 

 They are new forms. Some of them are so distinct that they 

 have been regarded as belonging to distinct genera. Here is the 

 experiment to prove that evolution is true, worked out upon a 

 scale and with a definiteness of detail which the boldest experi- 

 menter could not hope to attain, were he to live a thousand 

 years. The Horticulturist is the only man in the world whose 

 distinct business and profession is evolution. He, of all other 

 men, has the experimental proof that species come and go. 



It is stated that Prof. Carl Barus has constructed a new top 

 for educational purposes. The " peg " of the top consists of a 

 writing stylus, adapted to pencil a graphite record of its motions 

 upon a slate or sheet of paper. The motion of the " peg " simu- 

 lates the motion of procession about a moving axis, which, in its 

 turn, is in both rotational and translational motion. The complex 

 spiral and cycloidal curves which may be thus obtained present an 

 exceedingly beautiful appearance. 



