44 NATURAL REPRODUCTION OF FORESTS. 
trees do not germinate until the second year after being com- 
mitted to the soil, the various thinnings ought to be regulated 
according to the growth and progress of the young seedlings, 
until all the timber is felled, except the reserved standards or 
seed-bearing trees. These should be left for some time in order 
to complete the final sowing of seed, and also to assist in pre- 
venting the surface of the soil from drying up, as well as retaining 
a canopy for shelter against cold winds and unseasonable frosts. 
In connection with this, I shall point out some of the advan- 
tages to be derived in carrying out natural reproduction with a 
selection of species over the same operation in a wood consisting 
only of one species of tree. We will take a wood of any two 
species of mature hardwood trees ; as, for example, the oak and 
the beech, which are in many respects allied to one another. In 
considering regeneration in their case, at the outset we are beset 
with natural obstacles ; for no reliance can be placed in obtaining 
an annual crop of seed from those trees. One season there may 
be a good crop of acorns, while there is a dearth of beech mast. 
The following season there may be abundance of the latter, and 
none of the former; in fact, it is a rare chance to obtain a crop 
of seeds of both oak and beech in the same season. This draw- 
back, coupled with an uncertain climate and an inferior soil or 
subsoil, will greatly retard the process of regeneration. Conse- 
quently, with such obstacles, it will take longer time to complete 
the operation, and in certain cases it may end in failure. On the 
other hand, where a wood is composed of a varied selection of 
trees, reproduction can be produced in much less time; for we 
can almost rely upon obtaining seed from some of the varieties 
annually if the seasons are in any degree moderate; therefore, 
under such conditions the work can be safer and sooner performed 
than by the former example. 
I shall next draw attention to another method for the repro- 
duction of hardwoods by means of sowing the seed artificially. 
In order to render the process clear, there are several things 
which must be defined to some extent. I shall therefore class 
the seeds of hardwoods into three divisions—first, those seeds 
that require to be sown immediately after arriving at maturity, 
such as alder, birch, and elm; second, those which do not gene- 
rally germinate until the second spring after ripening, such as 
the ash, cherry, hornbeam, and service; third, those which fall 
into the category of heavy seeds, which cannot be dispersed to 
