A. FE. Verrill—The Bermuda Islands. 589 
of it and its poisonous effects. Its seeds, which are very hard, are 
eaten by many birds, especially by the Catbird, and in this way it 
could easily have been carried to Bermuda. About 50 species of 
the native plants have a wide distribution, occurring in the Old 
World as well as in America. 
In the chapter on geology I shall endeavor to show that most of 
the earlier plants and animals of the Pliocene Period were extermi- 
nated in Bermuda during the Glacial Period, owing to the distinctly 
colder climate and the frosts that must have prevailed, at that time 
in winter. Thus most of the plants of the present native flora have 
arrived here since the Glacial Period. The few endemic species, 
and some of the others, probably survived the Glacial Period, 
because they were able to endure the lower temperatures and some 
frost, or because they grew in very sheltered places, like the sinks 
due to fallen caverns. Probably the Flora in the pre-glacial periods 
may have been more tropical than the present one. 
25.—Destructive Effects of the Wild Hogs, Wood Rats, Snails, 
Slugs, ete. 
a.—Liffects of the Wild Hogs. 
Before the settlement of the islands the wild hogs had become 
very abundant. Henry May, in 1594, spoke of their leanness, for 
lack of food, in the winter season, when the cedar and palmetto 
berries were gone. It is probable that those herds of wild hogs had 
even then been on the islands for many years, and that they had 
eaten up or destroyed nearly all the native, edible, herbaceous plants 
long before the arrival of the settlers. This would account for the 
absence or rarity of plants having edible roots or herbage. The 
trees and shrubs having roots that they could eat would also have 
been damaged or exterminated, for wild hogs, when nearly famished, 
will root out and destroy the roots of many trees and shrubs that, at 
other times, they will not disturb.* 
* In the pine barrens of North Carolina I have formerly seen, in winter and 
early spring, large areas of pine lands where the half-wild hogs had dug up the 
roots of the pitch-pines, even of the larger ones, and had eaten the bark entirely 
off many of the upper roots. The ground under the trees looked, in many cases, 
as if it had been ploughed up in every direction, over large areas. The smaller 
trees were often overthrown and killed, while the larger ones were much 
damaged. 
