INTRODUCTORY LESSOJS'S 



IN 



STRUCTURAL BOTANY. 



SECTION 1.— THE BEGINNINGS OF PLANT LIFE. 



1. If tlie first rain of tlie wet season is followed by warm, sunny 

 weather, specks of green will soon appear among the dry stems of last 

 year's weeds; and in fence corners or other eddy nooks where summer 

 winds have drifted seeds and covered them with dust, you may find per- 

 fect mats of baby j)lants. "With a shovel skim off a few square inches of 

 this plant-bearing soil, and carefully examine it. Except a few green 

 needles, which you recognize as spears of grass, most of these little plants 

 seem to consist of white stems, which split at the top into pairs of green 

 leaves. Looking sharjDlj^ you may find between each pair of leaves a 



1 . Sf'cd of Bur-clover just be- 

 fore it (ippt'iirs above ground. 2. 

 Same three days older. 3. Mus- 

 tard. 4. Bur clover showing the 

 first and second plumule leaves; 

 the former simple (apparently), 

 the latter with three leaflets. 5- 

 Mallows (Malvaborealis), show- 

 ing the long-jjetioled seed leaves 

 (Cotyledons 1, and one jjlumulo 

 leaf unfolded. 6- Filaria (Ero- 

 dium), witli lobed or sub-com- 

 pouud seed leaves. 



tiny bud; or, in the older plants, this may have grown other leaves, which 

 curiously enough are not like the first two. (Figures 1 to G). Searching 

 through the shovelful of earth you will likely find plants in all stages of 

 growth, from swollen and sprouting seeds to stems, which are just push- 

 ing their bowed leaf-heads into the sunlight. Here, then, is material 

 from which you may learn how plants grow; a lesson, remember, which 

 no text-book or schoolmaster can teach you. It will be easier, however, 

 since most of these early wild plants come from very small seeds, to take 



