THE EXTENSION 19 
Study of birds in general. Some time should be given 
to the discussion of birds in general. This makes it possi- 
ble for the children to tell of any interesting observations 
made, or work done, to report new birds seen since the last 
lesson, and also to ask questions concerning birds which 
they could not identify, or other points about which they 
are doubtful. <A little time may be taken for this general 
work at each lesson, but when a few minutes can be given 
at other times, possibly during the morning exercises, this 
helps to keep up the interest of the children. 
Correlation of bird study with other subjects. While 
bird study seems to belong primarily in the nature study 
course, it may be correlated with other subjects. 
The most natural and practical correlation can be made 
with the subject of agriculture, by having the children 
study the relation which the birds bear to their work along 
this line. As many of the boys in our publice schools will 
be the agriculturists of the future, they should understand 
that the birds are the natural check to those pests which 
destroy our crops, and that the increase of these feathered 
workers will tend to add to the agricultural prosperity of 
our country. 
Bird study may also be used with especially good re- 
sults as a basis for occasional lessons in language and com- 
position. This furnishes the children with a topic in which 
they are naturally interested, and one which touches their 
every-day lives, so that they are able to give personal ex- 
periences. 
Some excellent problems can be prepared on the eco- 
nomic value of birds, and in this way bird study can be 
correlated with arithmetic. The following problems may 
serve as illustrations: 
If a meadowlark carried 10 cutworms to its young in 
one hour, and continued this for ten hours a day, how 
many of these insects would be eaten by this brood during 
the day? Allowing 20 broods to the square mile, how many 
cutwerms would be eaten daily by the meadowlarks in 
your county ? 
. There are five marsh hawks on Mr. Smith’s farm. How 
many mice will they destroy daily, if each hawk eats one 
mouse at a meal and has five meals each day? If each 
mouse caused Mr. Smith a loss of two cents, how much 
money would the hawks save him each day? How much 
would they save him during the year? 
