190 ECOLOGY 



only in those places where the hypothetical Tertiary climate still 

 predominates. 



If we need still further illustration, we might mention the fact 

 that agriculture, developed through centuries of human experience, 

 is a branch of ecology which long preceded methodical science. In 

 agriculture man took the household economy of plants into his own 

 hands in order to provide them with the necessary light, the most 

 propitious time for germination and ripening of the seed, and the 

 most suitable soil, paying due regard, however, to the succession of 

 seasons peculiar to the country and to the meteorological conditions. 



A botanical garden to-day, richly equipped with natural planta- 

 tions of every kind, greenhouses, moist and dry, hot or warm, bright, 

 or illumined by cool, green light, shows how many plants, native to 

 all climates and having the most varied requirements, may actually 

 be brought together in a small space by means of the careful imita- 

 tion of those conditions which we observe in the immense extent of 

 territory stretching from equator to pole. Progress in horticulture 

 denotes a minute observance of the vital phenomena of all the plants 

 we wish to assemble about us, and physiological investigation of the 

 effect of temperature and season give us the knowledge necessary 

 to change winter to spring in our drawing-rooms and conserva- 

 tories. 



Humanity gladly claims its share of the achievements which 

 beautif}^ existence. Universal cultivation of the intellect cannot 

 remain unaffected by results, which, together with those of other 

 branches of natural science, escape from their special field to become 

 so widely disseminated as to fill the thoughts of man and counter- 

 balance the effect of the strictly logical, mathematical point of view. 



Ecology has arisen from the need to unite originally separate 

 branches of science in a new and natural doctrine; it is characterized 

 by the breadth of its aims, and its peculiar power and strength lie 

 in its ability to unite knowledge of organic life with knowledge of 

 its home, our earth. It assumes the solution of that most difficult 

 as well as most fascinating problem which occupies the minds of 

 philosophers and theologians alike, namely, the life-history of the 

 plant and animal worlds under the influences of space and time. 



