44 THE BOOK OF FORESTRY 
Rodents consume enormous quantities of seed and in 
parts of the West seed collectors often get a large part 
of their supply from squirrel hoards Often seeds may 
dry out before they germinate or if they do start te 
put out the little roots they may find that the soil 
conditions are uncongenial and hence die very quickly. 
Different species demand different conditions for a 
proper germination bed. Some trees like poplar and 
paper birch find congenial surroundings for seed germ- 
ination in the ashes of a recent forest fire, because their 
seed germinates most readily upon mineral soil. When 
large tracts of spruce or pine country have been burned 
over these species often seed in upon the burn owing 
to the distance their hght seed may be carried by the 
wind. 
Other trees find moist soil and full sunlight abso- 
lutely necessary and hence willow seed dislodged by 
the wind may be carried downstream upon the water 
and find lodgment upon some warm sandbar, there 
germinate and grow most luxuriously. Still other trees 
find conditions favorable to germinate upon rotten logs, 
and it is no uncommon sight in the North Woods to 
see a row of yellow birches with an arch eight to ten 
inches high under the base of the trees, showing that 
seed had fallen upon a moist rotten log, had germinated, 
sent roots down to the ground and now that the old 
log has rotted away, the row of trees appears to be 
growing with part of their roots out of the ground. 
Whatever soil the seed falls upon the location must be 
the kind needed by the species or else the young seed- 
ling will last but a short time. 
In addition to perpetuating their kind by means of 
seed certain trees have the faculty of sending up 
