LAMARCK'S THEORY OF DESCENT 



297 



" A very dry spring-time is the cause of the grass 

 of a field growing very slowly, remaining scraggy and 

 puny, flowering and fruiting without growing much. 



"A spring interspersed with warm days and rainy 

 days makes the same grass grow rapidly, and the har- 

 vest of hay is then excellent. 



" But if any cause perpetuates the unfavorable cir- 

 cumstances surrounding these plants, they vary pro- 

 portionally, at first in their appearance and general 

 condition, and finally in several particulars of their 

 characters. 



" For example, if some seed of any of the grasses 

 referred to should be carried into an elevated place, on 

 a dry and stony greensward much exposed to the 

 winds, and should germinate there, the plant which 

 should be able to live in this place would always be 

 badly nourished, and the individuals reproduced there 

 continuing to exist under these depressing circum- 

 stances, there would result a race truly different from 

 that living in the field, though originating from it. 

 The individuals of this new race would be small, 

 scraggy, and some of their organs, having developed 

 more than others, would then offer special proportions. 



"Those who have observed much, and who have 

 consulted the great collections, have become con- 

 vinced that in proportion as the circumstances of 

 habitat, exposure, climate, food, mode of life, etc., 

 come to change, the characters of size, form, propor- 

 tion between the parts, color, consistence, agility, and 

 industry in the animals change proportionally. 



" What nature accomplishes after a long time, we 

 bring about every day by suddenly changing, in the 

 case of a living plant, the circumstances under which 1 

 it and all the individuals of its species exist. J 



" All botanists know that the plants which the)?? 

 transplant from their birthplace into gardens for cul- 

 tivation gradually undergo changes which at last 

 render them unrecognizable. Many plants naturally 



