(See Frontispiece.) There are no vessels or pores in coniferous wood such as one sees so prominently in oak and ash, for example.
(See Fig.

22.) [Illustration: FIG.

22 .-- Cross sections of a ring-porous hardwood (white ash), a diffuse-porous hardwood (red gum), and a non-porous or coniferous wood (eastern hemlock).

X 30.
_Photomicrographs by the author._] The structure of the hardwoods is more complex.

They are more or less filled with vessels, in some cases (oak, chestnut, ash) quite large and distinct, in others (buckeye, poplar, gum) too small to be seen plainly without a small hand lens.