ee 
The Habitat of the Juniper. 183 
which is a large tree in the swamps of Florida, covers also the 
driest ridges of the eastern Rocky mountains, with a enarly 
growth and hard texture, supplying the most lasting poles and 
posts. This latter species is also noticeable as having the widest 
distribution of all American forest trees. In fact, few trees seem 
so indifferent to climatic and soil conditions. From semi-tropical 
Florida to the cold shores of New Brunswick, and from the humid 
Atlantic coast it crosses the continent and the snow-covered 
Rockies to British Columbia and Washington.* It associates as 
well with the oak, hickory and magnolia in the rich river hot- 
toms, or with the cypress, ash and tupelo in the swamps, as with 
the pine on the hot sands and barren mountain sides. ‘Thanks 
to the taste of the birds for its berries, it finds ready dissemina- 
tion within this wide field, forming with the equally frugal aspen 
and cottonwood the very foremost advance guard of the forest. 
On the dry hot mesas and in the arroyos of tlte southwestern 
tier of our states and territories we meet a different set of skir- 
mishers following up the huge cacti and agaves, which together 
with the tree yuccas, penetrate into the very desert. In these re- 
gions the mesquite or algaroba and others of the acacia tribe 
form the second phalanx, as it were, gradually advancing their 
lines in spite of adverse conditions. In other regions the pine, 
satisfied with but scanty favor of soil moisture, and the spruce, 
able to sustain life in shallow soil, and the fir, in the higher, 
colder and wetter elevations, sometimes much stunted, form the 
skirmish line. These improve the soil in its moisture conditions 
by their shade, and by the foliage and litter falling and decay- 
ing they deepen the soil, forming a humus cover. The duff that 
is found covering the rocky subsoil of the Adirondacks is formed 
in this way at the rate of about one foot in 500 years. They are 
soon followed by the birche, maple, elm and ash and in moister 
situations by the oak—first, that hardy pioneer, the black oak 
tribe, and then the more fastidious white oak, with whom the 
slower but persistent hickories, beeches and other shade-endur- 
ing species begin to quarrel for the right of occupancy of the 
ground, until the battle is no longer that of the forest against the 
elements and lower vegetation, but between the mighty con- 
querors themselves. This struggle we can see going on in our 
primeval forests, wind-storms and decay acting as allies now to 
* According to some authorities the juniper found beyond the Rocky 
mountains does not include this particular species, Juniperus virginiand, 
