IO 
Journal of Agricultural Research 
Vol. XI, No. i 
over, with this species, as with all others, the reproduction is uniformly 
scattered over the township without any relation to the nearness or 
distance of the possible seed trees. Especially noticeable in this con¬ 
nection are the west, southwest, and south township transects, where 
white-pine reproduction over 5 years old occurs at a distance of 120 
chains from the nearest seed trees. The exceptional quantity of white- 
pine reproduction near the end of the southeast township transect occurs 
on a very favorable white-pine site, where the presence of white-pine 
snags proved that this species had formed an unusual percentage of the 
original forests. In this particular instance the mature forest contained 
about 5 per cent of white pine, while the reproduction now constitutes 
10 per cent of the stand. 
It is obvious that some source of seed other than the seed trees which 
escaped the fire is responsible for the occurrence of white-pine repro¬ 
duction in the burn. 
Pacific yew and dwarf juniper. —In the case of Pacific yew and 
dwarf juniper the theory of wind migration of seed to great distances is 
still more open to question. The important fact emphasized by the 
study of these heavy-seeded species is that reproduction is found only 
in localities where the trees occurred in the original forest. Before the 
fire Pacific yew was scattered throughout the area, and after the fire the 
reproduction was found always directly under or beside fire-killed yew 
snags. Dwarf juniper on the summit of Lookout Mountain grows close 
to the gnarled mats of dead juniper shrubs and could be found nowhere 
else in the entire township. 
This peculiar and consistent limitation of occurrence argues against 
the possibility of regarding such reproduction as the result of seed 
deposited by birds. If birds were the agents of migration, the repro¬ 
duction would have been found elsewhere than in the immediate vicinity 
of yew snags or dead juniper shrubs. Careful examination of the fire- 
killed specimens of both yew and juniper determined beyond doubt that 
they did not live through and produce seed after the fire; moreover, 
there are no green trees of seeding age of either species left within the 
burned areas. Neither of these sources of seed, therefore, can be held 
responsible for the reproduction of yew and juniper in the Columbia 
bum. 
THE DUFF, THE PRINCIPAL FACTOR IN REPRODUCTION AFTER THE FIRE 
The foregoing facts first cast a doubt upon the long-accepted theory 
of the restocking of large forest burns by the process of wind migration 
and finally proved it untenable. As the study progressed and this fact 
grew steadily more convincing, there arose naturally the question, 
“What was the source of seed for all this reproduction?” The answer 
to this question also developed naturally through the accumulation of 
evidence throughout the bum. It was found that the reproduction 
