64 ILLINOIS ACADEMY OF SCIENCE 



are now produced by cuttings, but originally came from 

 stock which Avould grow that way only with difficulty. 



All plants raised for any considerable length of time 

 by division, like tubers, bulbs, cuttings, buds or grafts, 

 gain the power to produce roots abundantly, and at the 

 same time they lose the power, sooner or later, to pro- 

 duce seeds. By continually exerting themselves along 

 particular lines plants develop new powers along those 

 lines, and by continued idleness along other lines (seed 

 production) they lose the powers they originally had. 



In a wild state plants have to fight for existence in a 

 world covered with other plants. When man domesti- 

 cated certain plants he protected them from weeds. As 

 a consequence of not having to fight for room against 

 other plants, our domesticated kinds have lost the power 

 of so fighting, and are unable to maintain themselves 

 when deserted by man. Idleness along that line caused 

 a loss of power on that line. There is no selection in 

 this. Man did not select plants because of their inability 

 to protect themselves. 



Plants produce seeds. To casual observation, a seed 

 looks like a dead object, but it came from a living plant 

 and it has life. In that life there is the power of 

 sprouting and growing into a new plant like that from 

 which the seed came. But let the seed lie idle for one, 

 two, three or more years, and that power gradually de- 

 clines and finally ceases to exist. The loss of power due 

 to idleness extends to the seed stage, and continued loss 

 of power means loss of life. In the seed, life and power 

 are one and the same. 



Flagellata are protozoa which multiply by division. 

 Dallinger subjected these animals to heat and found them 

 dying at 74 degrees, Fahr. But by beginning at 60 de- 

 grees and gradually increasing the temperature he finally 

 got them to stand 158 degrees without dying. Several 

 years were required to accomplish that result. There 

 was no selection in this. The final animals were simply 

 divisions from the original ones. By continually exer- 

 cising the powers they had, they acquired powers they 

 did not have before. 



