"I saw different kinds there. Are they all useful?"
"Some species contain nuts which are very fine, but are never eaten raw. They must be roasted."
"When Jim and I were down there this morning we saw at least a dozen different kinds of plants growing together in a space not three feet square. We both wondered why each kept on growing in its own way, from the same kind of soil. Now, don't the plants get all they are made of from the same soil? And if that is so, why don't they grow to be the same things?"
"Of course, like the animal kingdom, the germ[p. 85] of each is different, but each takes the identical substances from the same soil, and converts them into entirely different products. One will make a gum; the other produces a kind of milk; others will turn out a hard substance, like the outer portion of the nut; some will make a vegetable good to eat; others will yield a poison, and yet all are from the same soil."
"That is what I mean. Even though the plants are different, why is it that one will extract one thing and another something else?"
"It is due to what is called irritability or sensitiveness in plants. One plant is sensitive to the flow of certain juices, and is irritated, so that it is set into activity when different kinds of substances are carried along the pores or deposited in the cells. As a result, this irritation causes the plant to take only certain ones and reject others, and its tissues are thus built up only by such elements as its sensitiveness selects."
The training of the warriors with the new guns was a stirring sight for the boys, who could not help but be present during most of the time during the two days preceding the departure for the country of the Tuolos.
Ralph and Tom begged permission to accompany the party, and this was a natural request, because they had been rescued from this tribe the year before.