Page:Parsons How to Know the Ferns 7th ed.djvu/53

 stature dwindles with the increasing cold, and we seldom encounter them on our winter walks. The sterile fronds of a number of the Shield Ferns endure till spring. The Purple Cliff Brake and the Walking Leaf are also proof against ice and snow. Even in the middle of January the keen-eyed fern hunter may hope to make some discovery of interest regarding the haunts and habits of his favorites.