14 BULLETIN 606, U. S. DEPARTMENT OF AGRICULTURE. 
Diffuse-porous woods: 
Tyloses generally lacking — 
Tupelo gum Nyssa sp., sapwood. 
Wild red cherry Primus pennsylvanica, heartwood. 
Tupelo gum Nyssa sp., heartwood. 
Basswood Tilia americana, heartwood. 
Silver maple Acer saccharinum, sapwood. 
Tyloses scatteringly developed — 
Red gum Liquidambar styraciflua, sapwood. 
Tyloses not present — 
Yellow birch Betula lutea, heartwood. 
Sweet birch Betula lento, heartwood. 
Red birch Betula nigra, heartwood. 
White-heart beech Fagus atropunicea, heartwood. 
GKOITP II. 
(Woods which were moderately difficult to treat in the tests.) 
Ring-porous woods: 
Tyloses present — 
Mockernut x hickory Hicoria alba, heartwood. 
Hackberry Celt is occidentalis, heartwood. 
Rock elm JJlmus racemose, heartwood. 
Chestnut Castanea dentata, heartwood. 
J) iff use-porous ivoods: 
Tyloses present — 
Black 2 willow Salix nigra, heartwood. 
Largetooth aspen Populus grandidentata, heartwood. 
Sycamore Plata mis occidentalis, heartwood. 
Tyloses not present- 
Sugar maple Acer saccharum, heartwood. 
Silver maple Acer mccharinum, heartwood. 
GROUP III. 
(Woods which were very difficult to treat in the tests.) 
Ring-porous ivoods : 
Tyloses present — 
Bur oak Quercus macrocarpa, heartwood. 
White oak Quercus alba, heartwood. 
Diffuse-porous woods: 
Tyloses present — 
Red-heart beech Fagus atropunicea, heartwood. 
Red gum Liquidam bar styraciflua, heartwood. 
Group I. — All the specimens of Group I treated in the cylinder 
experiments were complete^ penetrated at 100 pounds pressure per 
square inch. An average absorption of more than 12 pounds per 
cubic foot was obtained in the cylinder treatment, and an average lon- 
gitudinal penetration of over 8 inches was obtained in the penetrance 
experiments, with the exception of two species, hackberry, which re- 
ceived slightly less than 12 pounds of oil, and sweet birch, which re- 
ceived only 3.85 inches of longitudinal penetration. The low longi- 
tudinal penetration in sweet birch was due to crooked grain, the oil 
1 Hickory might be placed in Group I, as it showed good penetrations. The reason for 
placing it in Group II was that the absorptions were not so heavy as those obtained in 
the species given in Group I. 
2 Black willow specimens treated in the cylinder showed good absorptions and pene- 
trations. Specimens treated in the penetrance apparatus did not show very extensive 
longitudinal penetration. This species is put in Group II rather than in Group I, as it 
is known to respond to treatment in a manner similar to large-tooth aspen, which in 
many cases is quite variable, partly on account of the irregular distribution of tyloses. 
