54 THE NKW METHOD 



will split into pieces as fine as the thinnest tissue 

 paper. It has also little lines about half an inch 

 long and one-eighth of an inch thick and perfectly- 

 straight. They are not in a straight line, but are 

 irregular. The leaf is ovate, or egg-shaped, and 

 varies from two to about four or five inches in 

 length. The margin is doubly-serrate and the 

 apex is very pointed. The base is rounded and for 

 about half an inch each side of the stem there are no 

 notches. The mid-vein is very large and also the 

 veinlets, but the veinlets can hardly be seen. The 

 leaf is net- veined, and on the upper side it is much 

 darker than on the under side. The veins can be 

 seen much more plainly on the under side than on 

 the upper. The leaves turn yellow in the autumn, 

 and grow lighter and lighter until they drop off. 

 The stem, or petiole, is about half an inch long, and 

 is quite thick. The seeds are contained in a tassel- 

 like cone, and there are hundreds of them in a single 

 cone. The cone is called a strobile. The strobiles 

 vary in shape on the different kinds of birch, some 

 being larger on one kind than those of another. The 

 seeds are of two different shapes, one kind being very 

 similar to the leaf of a cactus, being covered with 

 very, very fine hairs, that we cannot see without a 

 microscope. The other kind is in somewhat the 

 shape of a butterfly, having a body, two wings, and 



