( '54 ) 
The Brown Sort is larger than the Black, the Fif- 
fures at larger Diftances, the inner Subftance of* the 
Cortex darker, and the external Colour has feveral 
Degrees of Rednefs in the feveral Pieces. 
The Third or Grey Sort is fometimes found of a 
darker, fometimes of a lighter Colour, and the Inner 
Subftance of the Cortex is Brown ftreaked with 
White. It is much larger than the black Sort, many 
. Pieces being above a quarter of an Inch in Diameter, 
but the Nerve is fmaller in Proportion to the cortical 
Part. I have met with few Pieces of this Species 
above five’Inches in Length j but, as I already obferv- 
ed, nothing can be concluded from thence as to the 
Length of the whole Roots. ’ 
The Fiftures are here ftill fewer than in the brown 
Sort, and in fome Pieces fcarce any are to be met 
with. The fuperficial Corrugations are various in 
different Roots, fome being almoft wholly fmooth,.and 
in others the Wrinkles rather longitudinal than cir- 
cular. 
The white Kind, as . far as I can judge by the 
fmall Sample which I have of it, is of very differ- 
ent Sizes, ibrne Pieces of it being larger than any of 
the grey Sort, and the reft much lefs. The whitilh 
Colour- of the Cortex is mixed with a yellowifh Caft, 
and the nervous Part is very large in Proportion to the 
reft. Very few Fiffures are to be obferved therein, and 
hardly any reach fo deep as the Nerve. The other 
Corrugations are likewife very ftiallow, and moft of 
them longitudinal j but it feems to be more knotty 
than the other Kinds, and thefe Knots I take to be 
owing chiefly to the Fihrill^e which go out from the 
larger Branches of the Roots. The 
