some moss to take root and find home."

"And then the moss decays and makes soil for the ferns?"

"I suppose so."

Daisy stood looking with a countenance of delighted intelligence at the
great boulder, which was now to her a representative and witness of
natural processes she had had no knowledge of before. The mosses, the
brakes, the lichen, had all gained new beauty and interest in her eyes.
The doctor watched her and then scrambled up to his feet and came to her
side.

"Look here, Daisy," said he, stooping down at the foot of the rock and
shewing her where tufts of a delicate little green plant clustered,
bearing little umbrella-like heads on tiny shafts of handles.

"What is that Dr. Sandford?"

"Something wonderful."

"Is it? It is pretty. What is it, sir?"

[Illustration]

"It is a plant somewhere between the mosses and the lichens in its
character--it is one of the liverworts, and they are some of the first
plants to go in advance of superior vegetation. This is called
_Marchantia_."