Walks with the Children. 



'75 



Here also we found another kind of bark, namely, one 

 consisting of many thin layers easily splitting off from the 

 tree trunk. The use of birch bark by the American Indians 

 in building canoes and wigwams added no little interest to 

 the study of this tree. Observations on the bark brought 



FIG. 48. PERSIMMON. (DRAWN BY ROBERT LUM.) 



out the fact of its toughness, flexibility, smoothness, etc. 

 It required some close observation to discover why the out- 

 side is so white while the underlying layers are brown. At 

 length it was decided that the whiteness is due to the 

 bleaching action of sun and rain. Longfellow's lines in 

 Hiawatha, beginning, " Give me of your bark, Q birch- 



