4 THE NATURE AND WORK OF PLANTS 



be confused with the oak or beech, or the walnut 

 with the sycamore, wliile the pine and poplar are 

 so unlike that they might be distinguished even at 

 night. In the same manner the mosses and ferns 

 comprise many forms. The simple plants which float 

 upon the surface of the water in ponds also show 

 various colors, shapes, and methods of forming 

 colonies in evidence that they do not all live alike. 



4. The oaks, maples, elms, ferns, mosses, and pond 

 scums are not all of the same kind among them- 

 selves. — Now if one goes through a forest and looks 

 carefully at all of the maple trees he may see in a 

 half day's walk, he will find that they do not all 

 have the same appearance. 



In the Middle states one is very likely to see 

 " sugar maples " {Acer saccharum), large handsome 

 trees, over a hundred feet high, many of them with 

 grayish bark, large leaves, flowers greenish-yellow 

 in color, appearing at the same time as the leaves, 

 and the trunk is very full of a sweetish sap in the 

 spring. On the edges of swamps and in the low 

 grounds will be found other maple trees, with the 

 bark of the twigs quite reddish in color, leaves with 

 sharp-pointed lobes and some hairs on the veins, the 



