LYXXVIII LL; MATTSSON; 
form-quotients within a certain group of stems diverge from the mean form 
worked out. 
The bark breast-high of the Russian larch appears to be somewhat thicker 
than that of the European larch. i 
For both species the bark breast-high varies in quite the same degree. 
The general run of the bark-curve for stands of the two species is quite 
the same. The thickness of the bark is in a high degree dependent upon 
the absolute dimension of the tree, not so very much upon the place, or 
rather the importance, of the stem in the stand. 
The general thickness of the bark in different stands varies very much. 
These variations are to be connected with no certain quality of the stands, 
but are most probably to be looked upon as a question of race. 
This supposition is almost demonstrated by the investigations made by 
SCHOTTE of the origin of the seed from which the different stands have 
developed, the stands of Tyrolean origin showing a bark considerably thicker 
than those of Scottish origin. 
The taper of the bark of the Russian larch is a little different from that 
of the European larch. This difference, however, may possibly be considered 
as due to the inequality in height and age of the stems representing the two 
species. 
The distension by the root of the two species appears to reach breast-height 
when the stem is ten metres high, and then gradually to enlarge with increasing 
height of the stem. As to the amount, it is possibly in some degree dependent 
upon the density of the stand. It is a stem-quality, however, which requires 
to be examined much more closely. 
The second group of results can be briefly stated as follows. 
The variation of the stems within a stand according to form-quotient is 
very great. The total deviation amplitude reaches an amount of 25—27 
form-quotient units. 
The form-class-variation within the one diameter-class in which the mean 
stem of the stand is to be found reaches the same amount. 
The amplitude seems to vary with no certain character of the stand. 
The form-elass within a stand is a little higher for the smaller dimensions 
and a little lower for the greater ones. 
The mean form-elass of the stand is very closely connected with the mean 
height of the stand. This connection is so close that only for very few of 
the stands examined can there be demonstrated any deviation from the form- 
class determined by the mean-height. 
In these cases the deviation can be explained as due to the "density of 
the wood” in question "during the time of growth”. This character of the 
wood appeared, when closely examined, to be of such importance that different 
form-class-series for fully stocked and sparse stands could be worked out. 
The mean form-class of a stand, therefore, is to be determined with 
practically sufficient accuracy from the mean height of the stand, or, if greater 
accuracy is desired, from the latter and the density during the time of growth. 
Even greater accuracy is to be obtained in this manner than by using 
sample-trees, unless the number of those is greater than 40 or 50, and more- 
over they can be measured with very great accuracy. 
