characteristics of the framework?"

"It has big bones and little ones," cried Della.

"Good for Delila! The big bones are called ribs and the fine ones are
called veins. Now, will you please all hold up your leaves so we can all
see each other's. What is the difference in the veining between Ethel
Brown's oak leaf and Ethel Blue's lily of the valley leaf?"

[Illustration: Ethel Brown's Oak Leaf]

After an instant's inspection Ethel Blue said, "The ribs and veins on my
leaf all run the same way, and in the oak leaf they run every which
way."

"Right," approved Helen again. "The lily of the valley leaf is
parallel-veined and the oak leaf is net-veined. Can each one of you
decide what your own leaf is?"

"I have a blade of grass; it's parallel veined," Roger determined. All
the others had net veined specimens, but they remembered that iris and
flag and corn and bear-grass--yucca--all were parallel.

"Yours are nearly all netted because there are more net-veined leaves
than the other kind," Helen told them. "Now, there are two kinds of
parallel veining and two kinds of net veining," she went on. "All the
parallel veins that you've spoken of are like Ethel Blue's lily of the
valley leaf--the ribs run from the stem to the tip--but there's another
kind of parallel veining that you see in the pickerel weed that's
growing down there in the brook; in that the veins run parallel from a
strong midrib to the edge of the leaf."

James made a rush down to the brook and came back with a leaf of the
pickerel weed and they handed it about and compared it with the lily of
the valley leaf.

"Look at Ethel Brown's oak leaf," Helen continued. "Do you see it has a
big midrib and the other veins run out from it 'every which way' as
Ethel Blue said, making a net? Doesn't it remind you of a feather?"

They all agreed that it did, and they passed around Margaret's hat which
had a quill stuck in the band, and compared it with the oak leaf.

"That kind of veining is called pinnate veining from a Latin word that
means 'feather,'" explained Helen. "The other kind of net veining is
that of the maple leaf."

Tom and Dorothy both had maple leaves and they held them up for general
observation.

"How is it different from the oak veining?" quizzed Helen.

"The maple is a little like the palm of your hand with the fingers
running out," offered Ethel Brown.

"That's it exactly. There are several big ribs starting at the same
place instead