ow how are we to remember all those hard names?

Here is a jingle that perhaps will help us:--

_Coxa_ first, and then _trochanter_,
Number three the _femur_ stands,
After this, the long, straight _tibia_,
And last of all the _tarsus_ comes.

Now let us see who can learn it first.

Charlie says we are taking a good deal of trouble over the hind legs of
a grasshopper.

[Illustration]

Very true, Mr. Philosopher, but let me tell you something.

When we have learned the names of the segments in the grasshopper's hind
leg, we have learned the names of the segments in the legs of all
insects.

You see all the legs are made on one common plan, and it is very
convenient, as you will soon see, to have the parts named.

What a fine set of drawings of the grasshopper's hind leg we have!

Why do you suppose the coxa and trochanter are so small?

Yes, John, it is in order that the leg can move easily.

The grasshopper can turn its leg in almost any direction because of
these small upper segments.

It can put its leg up over its head if it wants to. Next to the little
coxa and trochanter is the longest and largest segment in the
grasshopper's leg; I suppose nobody remembers its name.

Listen to little Nell,--"number three the _femur_ stands."

So it does, and what a very useful femur it is!

If it were not for the long femur and the long, slender tibia, the
grasshopper would not be a grasshopper--it could not hop at all.

Watch the grasshopper, and see how he uses those long segments to jump
with.

[Illustration]

First he draws the tibia close up to the femur--now he is off!

He just straightened those long hind legs out with a jerk, and away he
went!

[Illustration]

What do you suppose the two little sharp spines at the end of the tibia
are for?

What, May? You did not see any spines?

[Illustration]

Look again.

See, Charlie has drawn them very plainly in his picture of the
grasshopper's leg. Mark them _s_, Charlie.

Now we must all look at Charlie's picture.

He says he thinks he knows what the spines are for--they are to keep
the grasshopper from slipping when he makes his leap forward.

I have no doubt Charlie is right.

May wants us to look at the beautiful little hinge x where the femur and
the tibia are fastened together.

[Illustration]

Let us mark it _X_.

See the little ball on the end of the tibia. How well it fits into the
hollow on the end of the femur.

In o