INTRODUTION 



Geological Strata : so that the positive evidence of the Rocks sup- 

 ports, so far as it goes, the grouping of Plants by comparison. 



On such grounds as these, Plants may be sorted into five main 

 Divisions, each comprising several Classes. They may be tabula' 

 as follows, while examples are given of familiar Plants, illustrating 

 the sort of living organisms which belong to each Class : 



Examples. 

 fSeaweeds and Freshwater Weeds 

 IMushrooms, Mildews, Moulds 

 /Mosses .... 



I Liverworts - - - - 

 I Ferns - - - - - 



Club-Mosses 



Horse-Tails - 



Pines, Firs, Yew - 

 fOak, Sunflower, Potato, Bean 

 IGrasses, Lilies, Palms - 



} 



i 



Class. 

 Algae 

 Fungi 

 Musci 



Hepaticae 



Filicales 



Lycopodiales 



Equisetales 



Coniferales - 



Dicotyledons 



Monocotyledons 



I M vision. 

 - Thallophytes. 



I - Bryophytes. 





- Pteridophytes. 



Gymnosperms. 

 I Angiosperms. 



A natural way of studying these would doubtless be to start from 

 the simplest and most primitive, and to proceed to those which are 

 more advanced : — that is, to follow the course which we believe 

 that Evolution has taken. It is, however, easier to begin the study 

 of the Living Plant from those of larger size, which are already 

 familiar objects to everyone, than from minute and unfamiliar 

 organisms, which can only be examined microscopically. It will 

 thus be best for us to take the Higher Flowering Plants first, and 

 to hold over the lower organisms to the end. 



One further general statement may be made regarding the Series 

 as thus laid out. It relates to the mode of life of the Plants con- 

 cerned. Many of the Thallophytes are water-growing Plants, such 

 as Seaweeds, and the Algae of freshwater streams and pools ; most 

 of them grow only where abundant moisture is present. The Mosses 

 and Ferns, though they appear as land-living Plants, require external 

 liquid water for completing one essential stage in their life-history : 

 without it they fail. On this ground they may be -ailed the 

 "Amphibians" of the Vegetable Kingdom. But the Seed-Plants 

 are not thus dependent upon external liquid water. The gen< 

 conclusion follows that Vegetation began in the water, that it spread 

 later to the land, and that it found its climax in the Seed- Bearing 

 Plants of the Present Day. This is the fundamental idea xv h» h should 

 underlie all Ecology, that branch of the Science which connotes 



