162 NATURAL HISTORY OF THE FARM 
it can find for cordage. Many birds weave shorter fibers into 
the walls of their nests. Most birds find suitable upholster- 
ing fibers for cushioning the eggs—horsehair or feathers or 
thistledown. And the robin mixes grass blades and bast 
fibers with the clay out of which he buildshismudnest. The 
birds know how to find proper raw material in great variety. 
Let us in the following study examine some of these un- 
developed fiber resources. 
Study 20. Native fiber products 
This is a study for the day when the weather is most un- 
favorable for field work; when the cold is too bitter or the 
blast too fierce for prolonged work outdoors. Then, certain 
fiber products may be gathered quickly and taken inside for 
examination; but a satisfactory range of materials for this 
work may be had only by gathering some of them in advance. 
1. Nests of birds, especially of Baltimore orioles. These 
nests are easy to find in winter, being suspended conspicu- 
ously from elm boughs high above the roads, but they are not 
easy to reach. The twigs bearing them may be clipped off 
with a long-handled pruner. 
2. Nests of mice, especially of deer mice. These are built 
in the branches of bushes in the woods. 
3. Cotton-bearing seeds of milkweed, etc., should be 
gathered in autumn at the ripening of their pods. 
4. Herbaceous stems may be gathered for their bast fiber 
at any time after maturing, and some, such as dogbane and 
milkweed, should be gathered as a part of this exercise; but 
in order to obtain the bast readily, the stems should have been 
gathered earlier and ‘‘retted’’ for a week or more (as neces- 
sary, according to species) in water. 
5. Coarser fibrous materials in variety. The bast strips 
of linden are obtained by stripping the bark from young 
trees in midsummer, when full of sap, and drying it thor- 
