26 THE STORY OF THE PLANTS. 



history of the process which we call creation or 

 evolution. 



The earliest plants, we saw, were in all prob- 

 ability mere tiny green jelly-specks, floating free 

 in water, and taking from it small quantities of 

 dissolved carbonic acid, which they manufactured 

 for themselves into green living material when 

 sunlight fell upon them. Now we shall have to 

 consider another peculiarity of plants (and of 

 animals as well before we can thoroughly under- 

 stand the first stage in the upward process which 

 leads at last to the pine and the lily, the palm 

 and the apple. 



Plants are made up of separate parts or ele- 

 ments, known as cells^ each of which consists of a 

 thin cell-wall, usually containing living material. 

 The very simplest and earliest plants, however, 

 consist of a single such cell apiece; they are 

 specks of green jelly, enclosed by a cell-wall, 

 alone and isolated. In such cases, when the cell 

 grows big and divides in two, each half floats off 

 as a separate cell, or a separate plant, and con- 

 tinues to divide again and again, as long as it can 

 get a sufficient amount of carbonic acid and sun- 

 light. But in some instances it happens that the 

 new cells, when budded out from the old ones, do 

 not float off in water, but remain hanging to- 

 gether in long strings or threads, in single file, as 

 you may see in certain simple forms of hair-like 

 pond-weeds. These weeds consist of rows of 

 cells, stuck one after another, not unlike rows of 

 pearls in a necklace. Of course the individual 

 cells are too small to see with one's unaided eye ; 

 but under a microscope you can see them, joined 

 end to end, so as to form a sort of thread or long 



