THUYA PLICATA AND T. OCCIDENTALIS 177 
and their variations ; (2) the T. Orientalis, or Biota, 
containing one and its many varieties ; and (3) the 
Thujopsis has a group to himself with some, and 
even a genus to himself with others. 
In reading differences of the Table there should be 
no difficulty in pronouncing judgment as between 
the T. Plicata and the T. Occidentalis.. The one (T.. 
Plicata) has white streaks on the under-leaf, and the. 
other (T. Occidentalis) has-not. Not even Bertillon,. 
with all his thumb-print successes, could have in- 
vented a better system of identification than this. 
If more evidence is wanted, we suggest a look at the. 
glands conspicuous on the one (T. Occidentalis), and 
inconspicuous on the other (T. Plicata), The Plicata 
must be identified from the Japonica by its finer. 
leaves, denser habit, and several other points noted 
in the Table. It will be seen there that C. Japonica. 
has coarser leaves, with blunter obtuse points, and. 
here is constituted perhaps its most telling and easily 
appreciated difference from the other two. It has 
also more vertically placed boughs, and grows more 
closely than the other Thuyas. The question of 
smelling out trees or, to put it more prettily, the art, 
of telling trees one from another by the scent they 
produce, comes to the fore particularly among this 
group of trees. Lest any one smile at the idea, we 
ask in all faith and simplicity, Why should not a tree 
be known by its smell when it is the proud possessor 
of an odour peculiar to itself, equally and for the same 
reason that arose, which, called byanyname, still smells 
the same, or a violet, or any other flower is so known ? 
Why should one product of the vegetable world have a. 
monopoly of dispensing education in this direction ?. 
When we come to consider it further, it is a power: 
undenied to a turnip, or garden cabbage, not to — 
mention an onion ; and when we venture our ridicule 
on the onion, let it not be forgotten that a saying runs, 
