26 NOTES OF A BOTANIST 
treatise on the Physiognomy of Plants, which is by 
no means my intention here ; I will therefore 
sketch briefly such other traits as are most worthy 
to be noted. The trunks of the trees, except for 
this occasional dilatation at the base, do not actually 
depart from the normal tapering cylinder. There 
was, however, one form at Para, resembling a 
clustered Gothic pillar, as if one thick trunk had 
been formed by the union of several slender ones, 
whose flowers and fruit I could not obtain ; nor did 
I ever afterwards meet with it, so that I am unable 
to refer it to its genus, or even family. Another 
form — a deeply furrowed trunk, here and there 
positively perforated, so that birds and small 
monkeys could creep through the holes — I after- 
wards found to belong to the genus Swartzia, of 
the leguminous family. Not every species of 
Swartzia, however, has a perforated trunk, and the 
most notable example of that peculiarity I have 
seen was in a beautiful species (which I have 
called .S. callistemon) abundant on the Upper Rio 
Negro. 
Everybody knows that the trunks of palms are 
ringed, each ring being the scar of a fallen leaf ; 
and that the trunks of bamboos are both ringed 
and jointed, a diaphragm being stretched across the 
internal cavity at each joint. There are at least 
two genera of exogenous trees, Cecropia and 
Pourouma (of the family of Artocarps or Bread- 
fruits), which have the latter peculiarity. On the 
lower Amazon the cavities are often taken posses- 
sion of by ants, but in the roots of the Andes by 
bees, which afford great store of wax to the in- 
habitants of Maynas. 
