100 
northwest, where very frequently one sees hemlocks in rows as 
straight as if planted by hand. They are from seedlings which 
have started on decaying tree trunks. 
F. E. Lroyp. 
ROOTS OF THE HEMLOCK. 
The hemlock grove in the Garden has occupied its place on 
since its formation, and it is therefore known as a primitive for- 
est. It is indeed remarkable that the city of New York should 
have a small portion of the primeval woodland which once en- 
veloped so large a portion of the continent still intact within its 
‘ boundaries 
If one should make a study of the hemlock tree he would find 
that it does not grow well in ordinary clay, gravelly soil, or even 
loam, but that it thrives best when it is established in a piece of 
ground which is covered to some depth with decaying leaves and 
twigs. This decaying matter or humus is a wonderful substance, 
and makes up a world of life of itsown. It teems with bacteria, 
is pierced in a thousand directi tions by the glistening white 
threads of the moulds, and is inhabited in the upper layers by 
the threads and colonies of green algae, and by the green pro- 
tonemal threads of mosses and liverworts, all of which are busily 
engaged in breaking up the dead leaves and using their sub- 
stances for food. Into this mass the hemlock sends its finer 
roots for the same purpose. 
The voots of the tree are not able to take up the substance of 
the decaying humus by reason of some unknown character in 
not derive euch fo d from the surface layer of soil in the forest. 
Since the tree can not secure this ee = a a own elude 
it has entered into a partnership with t 
which will enable it to do so. By a association the threads of 
the moulds and mushrooms unite with the roots to form what is 
known as a mycorhiza. 
