484 Minnesota Plant Life. 



ing down the dim and distant ages to the very moment when 

 the first hving- particle appeared on the surface of the earth. 

 Thus, the child of two infinities, it baffles interpretation; for in 

 the heart of every flower is the riddle of the Sphinx. 



From such a conception the poet may derive his inspira- 

 tion and the moralist may instill his lesson. But it is the duty 

 of the student of science to put aside all feelings either of ex- 

 altation or depression and to endeavor to collect such facts as 

 arc attainable, even when he recognizes that ultimate explana- 

 tions lie far too deep to be reached by the plummet of human 

 thought. In such a spirit the plant has l)ecn c[uestioned by 

 modern science and somewhat is known of the story of its life. 

 In very simple fashion I shall endeavor to picture it as an 

 organism at work. 



Living substance. The essential groundwork of every living 

 organism is a material known as living substance, or protoplasm. 

 By no means all portions of an organism actually consist of 

 this living substance, although all portions have arisen through 

 its activity. It is as the spiders spin their webs, or as men 

 build their cities. The living substance is the organizing body 

 and the completed plant or animal is the resultant organiza- 

 tion. As long as the organism contains this lix'ing substance 

 it may be said to be alive ; but when the living substance is 

 destroyed throughout its body the organism is then said to 

 be dead. No longer held together by the forces inherent in 

 its builder it may be resolved again into the elemental sub- 

 stances from which it was constructed. Just so. to continue 

 the illustration, will a city, if abandoned l)y its inhabitants, 

 fall into ruins and fniall}' crumble into dust. 



Death of an organism ma}- be sudden or gradual. Thus 

 by fire, for example, a plant or animal may in a few moments 

 be converted from a living l)eing into a handful of ashes and a 

 wreath c^f smoke. Again, death may l)e sk)\v. creeping from 

 organ to organ, .'ind e\cn when the organism as a whole is no 

 longer li\-ing there may in some of its tissues still remain i)ur- 

 tions of the li\ing substance. The wliehning of Tonipeii by 

 llie fires of \'esn\ius might be taken as an illuslration of the 

 lirst condition and the gradual l)nt relentle>> niarcli ol a pesti- 

 lence mi^ht illustrate the other. 



