682 THE POPULAR SCIENCE MONTHLY, 



ning of agriculture. Success was not difficult in regions where 

 propitious conditions of soil and climate favored the propagation 

 of plants of great productiveness. Observation and experiment 

 next fixed the elements of a theory, limited at first to a few species, 

 then extended and perfected by degrees. To reach these feeble 

 beginnings by the rational methods of agriculture, a long series 

 of attempts marked by more failures than successes had to be 

 gone through. Gradually, however, the processes were improved ; 

 the resources increased, and the profits of vegetable production, 

 so long surpassed by those of the hunt and of cattle-raising, at 

 last prevailed over them ; and this determined the adoption of a 

 special kind of life, the consequences of which were destined to 

 transform the condition of man. 



Regarded as a whole, the cultivation of plants was a more com- 

 plex and more arduous problem than the domestication of ani- 

 mals. To subject animals, it was enough to capture and hold 

 them. They were then tamed as they became familiar, and after- 

 ward required nothing more than watching or protection. They 

 could themselves provide for their wants, or make them known 

 in a language easy to understand. They spontaneously sought 

 their food and fled from danger. The mothers suckled and de- 

 fended their little ones. Animal instinct thus saved the master 

 of the herd much trouble. Plants, on the other hand, although 

 their passive nature is apparently less rebellious to subjection 

 than the undocile character and self-will of animals, really opposed 

 more obstacles by the very fact of their lack of activity, on ac- 

 count of which they could not help and be sufficient for them- 

 selves. Constant watchfulness had to be exercised to see that 

 their growth was accomplished regularly, for their needs never 

 became evident till they were dying, and intelligent cares are 

 necessary to prevent this or remedy it. Taking the propagation 

 of plants under his charge, man had to choose a favorable soil for 

 them, to break it up by toilsome labor, to put the seed in at the 

 proper time, to stimulate their growth with manures, to furnish 

 them water, warmth, and light, according to their needs. Their 

 reproduction, in the wild state, was accomplished in the midst of 

 innumerable risks, under the laws of the struggle for existence, 

 and multiplicity of seeds could alone, in the face of a fearful loss, 

 make sure the duration of species. In the hard and incessant 

 struggle to which plants were given in the contest for ground 

 and a place in the sun, the most precious, which were also usually 

 weak and delicate, were liable to be smothered. To cause them to 

 increase, man had to interfere in the conflict, to extirpate useless, 

 vigorous, and aggressive species, and procure for those under his 

 protection conditions of development. It was necessary, there- 

 fore, to clear, plow, and weed ; to study the phenomena of vege- 



