236 FORESTRY IN FRANCE. 
sections, each of whichis dealt with separately. After the examina- 
tion and description of the temporary plots, the section (see Pl. VIII.) 
is divided into a number of equal compartments called affectations, 
and when the ground has once been completely worked over, the crop 
on each of these will always be within certain limits, in the same 
stage of development, and subjected to the same kind of treatment. 
Thus, if the trees are to be felled at the age of 120 years, and 
there are six compartments, the sixth may contain the young growth, 
aged from 1 to 20 years, the fifth young poles from 21 to 40 years 
old, and so on, the first containing the old trees which are to be 
felled. The compartments having been formed, each of them is then 
subdivided into compartments usually corresponding in number 
with the years over which the fellings within it are spread (twenty 
in this case), and, while the trees are being cut in the first compart- 
ment, clearings and thinnings of various recognised degrees are 
going on in the compartments of the others, until each in its turn 
arrives at the age at which the trees are to be removed; and it is 
clear that in this case also the forest will ultimately contain a due 
proportion of trees of all ages from 1 to 120 years, which is an 
essential condition. The working plan prescribes the order in 
which all this is to be done, and it lays down the number of cubic 
feet of timber of the oldest class which are to be taken out annually 
from the first or oldest compartment, so that the entire stock on it 
may be removed within the first period of twenty years, wind-falls 
and dead or dying trees being always taken first; each of the re- 
maining compartments is similarly dealt with when its turn to be 
felled arrives. The quantity of wood to be removed by thinnings 
cannot be prescribed by the working-plan, as they must be made 
to the extent which is judged necessary in order to develop the 
trees which are left. The forester’s art is to do this skilfully, and 
ultimately to remove the old trees in such a manner that they may 
leave behind them a young self-sown crop to take their place, and 
so on throughout successive generations. 
For a high-forest to be managed under the selection method, the 
arrangement is different. Here it is, of course, equally necessary 
that all the age-classes should be represented in due proportion, 
but instead of the trees or poles of each class being grouped to- 
gether in separate compartments, all classes are mixed indiscriminately 
over the entire area of the forest, and there is thus no necessity for 
the formation of affectations, or compartments, of the kind just 
described. Take for instance the mountain forest sketched in 
