The Origin of the different classes of the Higher Cryptogamia.
2
The Sub-kingdom of the higher Spore-plants, the Cryptogamia possessing a vascular system, was more prominent in early geological periods than at present.
3
It would appear then that the first class consisted of seedless plants, i. e. of the cryptogamia.
4
But the cryptogamia, in general, thrive best when they are protected from the direct rays of the sun.
5
As the conditions of the earth changed, the cryptogamia seemed to have dwindled away, while higher forms of vegetation asserted their supremacy.