Trelease — Botany During the 19th Century. 135 



How protoplasm carries " life," the nature of the reactions 

 t shows to stimuli of various kinds, causing it to work, to 

 change, to rest, to die, how it is moved to vary in the forms 

 of tissues and organs over the construction of which it pre- 

 sides, how it transmits characters of form and action from 

 parent to offspring and reverts now and then to ancestral 

 structures and traits in both animals and plants, are scarce 

 more than question marks on an otherwise clean page spread 

 out before the Twentieth Century, and it is not possible yet 

 to say whether they will receive their answer soon or always 

 remain unanswered. 



ECOLOGY. 



One of the most popular lines of physiological work to-day 

 concerns itself with special modifications and activities con- 

 nected with local environment and what may be called the 

 personal or individual needs of plants, in contrast with their 

 needs as a class. This is called biology by some and ecology 

 by others. 



Just before the end of the Eighteenth Century, a German, 

 Sprengel, observed a few hairs springing from the base of the 

 petals of a wild geranium, and, though he did not share the 

 impersonal teleological views that prevail to-day, he believed 

 that these hairs existed for a purpose, which he undertook to 

 find out. Under them he found glands secreting a sweet 

 fluid, nectar, which he saw was sheltered by them, but the 

 nectar was a further puzzle. Bees came to the flowers as he 

 watched, and removed the nectar, which the glands had 

 secreted and the hairs protected for them, and the question 

 seemed answered; for an idea, somewhat prevalent even yet, 

 that everything exists for the good of something else, — gen- 

 erally higher in the scale than itself, — was commonly held 

 in his day. Further observation, however, showed him that 

 the bees became dusted with pollen and that they uncon- 

 sciously transferred some of this to the stigmas of the flowers, 

 while rifling them of their sweets, and that this transfer, 

 long known as necessary in some manner for fertilization and 

 the quickening of the germ, could not otherwise take place 

 except by remote chance. Then he examined many other 

 kinds of flowers, and reached the broad conclusion that nectar 



