1905] WHITFORD—FORESTS OF FLATHEAD VALLEY 283 
2. Other things being equal, the plants whose seeds are in the burn 
first will gain the earliest foothold. 
3. Those plants that have seeds there early after fires will be 
those that have seeds’ well adapted for distribution. 
4. Of the plants that have their seeds equally well adapted for 
distribution, those with seed-bearing representatives standing nearest 
the burned area will have the advantage. 
5. Again, other things being equal, of those species that have 
their seeds equally well adapted for distribution and have seed- 
bearers equally near the clearing, the species that produce seeds most 
abundantly will be apt to win out in the struggle. 
6. The species that can resist fires the best are likely to have left 
standing in or near the area itself seed-bearing parent plants. 
7. The conditions of the soil must be such that it will permit the 
germination of the seeds that fall upon it. If the soil is too moist, 
too dry, too poor, or too much shaded, no matter how many seeds 
fall upon it, none will germinate. : 
These well-known principles will aid in the determination of the 
causes of the many complex conditions of forest growth after fires. 
Before the actual conditions of the clearings are considered, however, 
the ecological habits of another tree, the lodgepole pine, must be 
known. 
The lodgepole pine covers large areas in Swan valley, sometimes 
forming almost pure stands. It is able to exist and thrive in those 
moist areas where it has to compete only with the spruce and its 
associates. It is found mixed with all the other species in the meso- 
‘ phytic portion of the valley. Toward the borders of the meso-xero- 
phytic areas it is not so prevalent, though signs of it were noted west 
of Echo Lake and in the mesophytic portions of the west slope of the 
Mission Range. It does not advance into the prairie formation, 
however, so far as the bull pine and the Douglas spruce. Its alti- 
tudinal range was not investigated. It is difficult to tell whether 
or not this tree would maintain a stand in the Flathead valley if it 
Were not for the influence of fires. It is intolerant of shade, in which 
Tespect it may be ranked with western larch and Douglas spruce, 
Teproducing in open places only. No young trees were noted in 
€ shade, save an isolated poorly developed specimen now and then 
