48 THE WORMS. 
shrubs and trees. According to the same authority, during the Sikh 
rebellion an entire English regiment was forced to retreat before the 
myriads of blood- 
suckers, 
VALUE.—Leeches, 
from their extreme 
sensitiveness to at- 
mospheric changes, 
are sometimes used 
as barometers, but 
their principal value 
is in medicine. In 
Fic. 50.—Land-leeches of India, racing to attack one year 7,000,000 
some animal, were used in London, 
at $10 per 1,000, 
Earth-Worms.—The earth or angle-worms (Fig. 51) 
are cylindrical, and composed of numerous joints or seg- 
ments, each divided by a thin muscular partition. Upon 
examination, the lower portion of the segments will be 
Fic. 51.—Earth-worm (Lumbricus terrestris). 
found perforated with four rows of minute holes, through 
which extend bristles that are really the feet. These curve 
backward, and, by extending the head and throwing them 
out, the remainder of the body is pulled along, a fresh 
hold taken, and so on. They multiply by eggs that are 
protected by capsules, those of some kinds containing 
fifty eggs. 
VaLuE. — Eaten by the Indians, and valuable as preparing the 
earth for the reception of seeds.* 
* The amount of vegetable’ mold thus brought to the surface in a 
single year by worms amounts, according to Darwin, in some places to 
ten tons in a single acre; they rarely go below six feet, and it has 
