28 WOOD NOTES WILD. 
a pair of chickadees on a limb of a small tree. The 
song came from one of them; and when he shot up and 
away, he left me with a new understanding of the value 
of purity of tone. Nearly all small birds sing rapidly, 
too rapidly for appreciative hearing; but this little song- 
ster somehow has found out that one pure minim is 
worth a whole strain of staccato demi-semi-quavers. 
The chickadees sometimes employ a delightful form of 
response in their singing : — 
