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 saccharimim, sapwood. 



Tyloses scatteringly developed — 



Red gum Liquid am bar styraciflua, sapwood. 



Tyloses not present — 



Yellow birch Betula lutea, heartwood. 



Sweet birch Betula lento, heartwood. 



Red birch Betula nigra, heartwood. 



White-heart beech Fagus atropwiicea, heartwood. 



GKOL'P II. 



(Woods which were moderately difficult to treat in the tests.) 



Ring-porous woods: 

 Tyloses present — 



Mockernut 1 hickory Hicoria alba, heartwood. 



Hackberry Celt is occidental's, heartwood. 



Rock elm Ulmus racemosa, heartwood. 



Chestnut Castanea dentata, heartwood. 



Diffuse-porous woods: 

 Tyloses present — 



Black 2 willow Salix nigra, heartwood. 



Largetooth aspen Populus grandidentata, heartwood. 



Sycamore Plat-anus occidentalis. heartwood. 



Tyloses not present — 



Sugar maple Acer sacchanun, heartwood. 



Silver maple Acer saccharinvm, heartwood. 



GROUP III. 



(Woods which were very difficult to treat in the tests.) 



Ring-porous woods: 

 Tyloses present — 



Bur oak Quercus macrocarpa, heartwood. 



White oak Quercus alba, heartwood. 



Diffuse-porous woods: 

 Tyloses present — 



Red-heart beech Fagus utropunicea, heartwood. 



Red gum Liqitidam bar styraciflua, heartwood. 



Group I. — All the specimens of Group I treated in the cylinder 

 experiments were completely 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. 



