书城教材教辅科学读本(英文原版)(套装1-6册)
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第186章 第三册(11)

"Now, a glance at one of these feathers," he said, "will tell us that it consists of two parts. There is the long stem, which runs from the root to the very tip of the feather, and on either side of this is the blade or web.

"Let us examine the central stem first. The lower half of it near the root seems to be quite different from the upper half. Try and cut it across with your knife, Will." Will tried, but he found it no easy taskto cut through this part of the stem, for it was like strong, tough horn. However, he did cut it across at last, and then they saw that it was really a round hollow tube.

"Teacher calls this lower part of the stem the quill," said Fred. " It is thin, hollow, and extremely light, but it is very tough, strong, and elastic, and will bear a great deal of rough usage. The lower end of it forms the root, which holds it in the skin of the bird.