- 15 - 
Spencer, D. A., and Potts, CO. 
1933. Sheep raising in U. S. has changed greatly since pioneer period. 
U. S. Dept. Agr. Yearbook 1933: 264-273. 
p. 264: Sheep are also raised extensively in the grass-produc- 
ing areas of the Eastern and Central States, particularly in rolling 
and hilly sections . Since sheep are fond of a great variety of weeds 
and underbrush which cattle and horses do not relish, they are useful 
in keeping fields and fence .corners clean and in utilizing forage 
not so well adapted to other livestock. 
p. 267: Except where flocks are kept to produce purebred stock, 
special crops are seldom grown for the sheep, which -are generally 
turned onto pasture as soon as the grass begins to grow in the soring 
and remain there until the crop s have been harvested, when they are 
usually given the run of the fields to graze and to clean up the 
weeds , and remain there until snow falls. They are then carried 
through the winter on hay and some of the unsalable roughage, with 
little or no grain. 
Forest. Brush, and Grass Fires 
Forest, brush, and grass fires destroy all kinds of wild life, includ- 
ing pollinating insects. The practice of burning fence rows, railroad 
right-of-ways, pastures, etc., is highly detrimental to wild pollinating 
insects, most of which nest in or near the ground. 
Sims, I. H., Munns, E. N., and Auten, J. T. 
1938. Management of forest soils. U. S. Dept. Agr. Yearbook (Soils 
and Men) 1938 t 737-750. 
p. 741 1 Heavy cutting has commonly been followed by fire, and 
examples of serious soil deterioration due to this combination of 
treatments can be found in practically every forest region of the 
country. Some 60 million acres of land have been so completely dev- 
astated by this combination that they are unlikely to reforest 
naturally and must be planted. The total is being swelled currently 
by the addition of 850,000 acres each year, three-fourths of which 
is land formerly occupied by conifer stands. 
When cut-over land is burned the fire accomplishes in minutes 
the degree of litter removal that would be achieved naturally only 
after several years... This sudden removal of the litter and its 
living population sets in motion a chain of events leading directly 
to deterioration or loss of the soil. 
p. 743: Extreme soil temperatures frequently develop during 
the great conflagrations and humus in the upper horizons is oxidized 
