tibia and the fibula connect the ankle to
the knee. The femur connects the knee
to the pelvis.
The forelegs of four-legged mammals
can be compared to human arms. Like
arms, forelegs can hit, pull, and dig. But
forelegs also support and move the body.
The bone in the upper foreleg is called
the humerus. The humerus connects the
scapula (shoulder blade) to the knee.
The radius and the ulna connect the
knee to the ankle.
Most animals that live on land have legs. Legs support an animal’s body and allow it to
get around.
BRITANNICA STUDENT ENCYCLOPEDIA Leg 123
Legs of Other Animals
Amphibians, reptiles, and arthropods—
which include insects, spiders, crustaceans,
and centipedes—also have legs.
Like mammals’ legs, most have muscles,
joints, and segments. However, these
animals’ legs are usually attached to the
sides of the body, not underneath. Most
amphibians and reptiles have four legs.
Arthropods have from three to about
200 pairs of legs. Arthropods’ legs have a
hard outer covering instead of bones
inside.
Birds have two hind legs, also with
muscles, bones, joints, and segments.
They are located under the body. Instead
of forelegs, birds have wings.
#More to explore
Arm • Bone • Foot • Knee • Muscle
Legislature
The group within a government that
makes the laws is called a legislature.
Republics and most modern monarchies
have legislatures. States and provinces
have them too. Old-fashioned monarchies
do not need legislatures because
the ruler makes the laws.
Many countries have adopted legislative
systems similar to that of either the
United States or Great Britain. The
United States legislature is called Congress.
Great Britain’s legislature is called
Parliament.
The United States separates the legislative
branch from the rest of the government.
In the United States, the president
is not allowed to be a member of Congress.
In Great Britain it is different. The
prime minister has to be a member of
Parliament.
Many legislatures consist of two groups,
or houses. In the United States and
Great Britain, the lower house has members
who are elected from districts. The
residents of a district vote for a member
to represent them. The upper houses are
chosen by other methods.
Israel, like many other small countries,
has a one-house legislature. Israel’s legislature
is called the Knesset. There are no
election districts. People vote for a party
rather than a candidate. A party gets the
same share of Knesset members as its
share of the nationwide vote. This system
allows small parties to have members
in the legislature.
Legislatures may have other duties
besides making laws. The U.S. Congress,
for example, must approve officials
and judges who have been appointed by
the president. It also has the power to
Members of Israel’s legislature stand after
hearing a speech by a foreign leader. The
legislature is called the Knesset.
124 Legislature BRITANNICA STUDENT ENCYCLOPEDIA
remove government officials from office
or to declare war.
#More to explore
Congress of the United States
• Government • Parliament
Legume
Legumes are flowering plants of the pea
family. The pods, or fruits, of these
plants are also called legumes. There are
more than 18,000 species, or types, of
legume. Some well-known legumes
include beans, peas, peanuts, and soybeans.
Legumes grow all over the world. Most
types grow naturally in warm or tropical
areas. Most of the legumes that are valuable
as crops are grown in mild climates.
Legumes can grow as herbs, vines,
shrubs, or large trees. Most have soft
green stems and flowers with five petals.
The flowers later grow into pods, which
hold the plant’s seeds. Pods come in a
variety of shapes, sizes, and textures. A
pod releases its seeds by splitting open
along two seams.
Legumes are an important source of
food because they are high in protein.
Beans, peas, and peanuts are legumes
that people commonly eat. Soybeans are
used to make such foods as tofu, soy
milk, ice cream, and soy sauce. Soybeans
are also used to feed livestock. Alfalfa
and clover are used as livestock feed, too.
Legumes also are useful in improving
the soil. They do this by adding nitrogen
to the soil. Nitrogen is a nutrient that is
important to all living things. The air
has a lot of nitrogen, but most organisms
cannot use it in that form. Most
plants get their nitrogen from the soil.
But legumes can take nitrogen from the
air. In the roots of legumes, special bacteria
turn the nitrogen into a form that
plants can use. When legumes are
plowed into the soil, they release nitrogen.
Other plants can then take up the
nitrogen through their roots.
#More to explore
Bean • Pea • Peanut • Plant
Leif Eriksson
Leif Eriksson was probably the first
European to visit North America. He
was a Viking. The Vikings were warriors
The protein
content of soybeans
is twice
as high as that
of meat.
Peas are legumes. The pods of a pea plant
split open to release the seeds, or peas,
inside.
BRITANNICA STUDENT ENCYCLOPEDIA Leif Eriksson 125
from northern Europe who traveled far
by sea during the Middle Ages.
Leif was born on the island of Iceland
sometime before AD 1000. He grew up
