142 THE NATURE STUDY COURSE. 



of external activities or environmental re-actions such as efforts 

 to get light, air, moisture and food, to distribute their seeds 

 and to adapt themselves to external conditions. This study 

 is called ecology, meaning literally the study of living plants 

 "at home" whether in forest, field, or garden. 



It will be noticed that the plant studies in Grade Seven of 

 the Manitoba Course are largely of this character. After the 

 common plants of a locality can be recognized and the 

 functions of the members of the plant body have been studied 

 objectively in an elementary way, the most interesting and 

 profitable subsequent plant studies in the public school will be 

 chiefly ecologic. 



Plant Societies and Zones. — If the pupils can be taken to a 

 height of land rising not too abruptly from a bog or weedy 

 pond which is partly enclosed by woods they are on the ground 

 where in small space the richest lessons in plant ecology can 

 be studied. First, there is the zonal distribution of plants. 

 Centring in the deepest part of the pond, circle after circle of 

 plant communities will be disposed before them. Nearest the 

 centre will be found the submerged milfoils, bladder-worts 

 and eelgrasses, needing little light and getting their gaseous 

 foods by direct osmosis, and requiring for apparent reasons 

 little or no root. 



In the zone of comparatively shallow water the water-lily 

 group trail their stout rootstocks along the muddy bottom, 

 and on spongy petioles long enough to reach the air float their 

 ample leaves upon the surface of the water. A wider circle 

 still growing in the water but with narrower leaves held 

 above it contains the pickerel-weeds and lizard-tails, the 

 arrow-leafs and bur-reeds. Farther out, sometimes in water, 

 sometimes in mud, stand the bulrushes and cat-tails, the 

 sedges and swamp-grasses in a compact and irregular zone, 

 each struggling with the other, one gaining an advantage here, 



