188 NATURAL HISTORY OF THE FARM 
nation as a candidate for president, in order to ally him 
with the common folks, he was presented to them as a 
rail-splitter. 
Events have moved rapidly since that day. The rail- 
splitter is well-nigh extinct. The rail fence has become 
expensive, and wire is taking its place. Another generation 
will see little of the old form of wooden fence, which in our 
day still exists side by side with modern wire and ancient stone. 
Whatever the form of a fence, if it bound a tilled field, it is 
bordered by a strip of ground, at least as wide as a whiffle- 
tree is long, that is a tension zone of wild life. On one side is 
the fence; on the other, the furrow. Between extends a strip 
of sod that the plowshare cannot reach, and this sod is full 
of lusty wild things, all senigelng for a place and a living. 
If the farmer mows it con- 
stantly, grass sod develops 
asinameadow; ifhemows 
it annually in winter, shrubs 
and vines possess it; if he 
neglects to mow it for a few 
years, treescomein. What- 
ever plants grow in it, it is 
a haven of refuge for their 
wild animal associates; if 
Fig, 72. Diagram of 4 erosssectionof'2 only grass sod, meadow-mice 
burrow; b, the runway of a meadow- : A 
mouse under the grass; c, the “form” of and shrews will make their 
ee oa furrow; and ¢, the runways under its cover; if 
briers and grass grow 
together, rabbits will make their forms or dig their bur- 
rows in the midst of it. Every post or stake or high 
point in the fence is a point of outlook and a resting- 
place for the birds of the fields. Perching, they drop the 
seeds of berry-bearing shrubs and vines. So, we see dog- 
woods and elders and sumachs and chokecherries and bram- 
