CHAPTER VI. 
ON THE DEFECTS IN TREES— ( Continued ). 
Where woody layers of irregular growth are found in 
timber, especially if there be alternation of colour extend¬ 
ing over many of them, they may be considered to 
indicate that the tree was not at all times in a healthy 
state, but that it had suffered from some cause, or from 
the failure in the nourishment it required to perfect the 
layers with regularity. 
Any departure, therefore, from the natural colour 
peculiar to the species, whether it embrace one or more 
concentric circles, or be locally situated, is prejudicial 
to the wood, and generally, if tried under the adze 
or plane, it will be found brittle and deficient in tena¬ 
city. Such logs should on no account have the preference 
of selection for important services in works of construc¬ 
tion, but should rather be used for minor purposes. I 
have noticed this defect in many varieties of trees, but in 
none is it more conspicuous than in the Kauri of New 
Zealand, these noble Pines being peculiarly liable to this 
whenever they stand exposed upon the north or equa¬ 
torial side. 
We occasionally see spots in timber, quite foreign in 
colour to that which is natural to it ; they may be seen 
in all parts, but are most common at or upon the butt- 
end of the log. These are not often of a very serious 
