232 ANATOMY OF THE GYMNOSPERMS 



/\<i(fiti/. Ray trachcids chiefly narrow, very unequal, often high, sometimes 

 present, then rather abundant and composing the entire ray when of 

 I or 2 cells only, usually absent from the higher rays. Medullary 

 rays contracted at the ends ; the upper and lower walls medium to 

 thick, unequal, frequently pitted or again entire or distantly pitted ; 

 the terminal walls thin, often curved and locally thickened ; the lateral 

 walls with round or oval pits, the orifice lenticular, 1-2, or in the 

 marginal cells and low rays, 6, per tracheid. Pits on the tangential 

 walls of the summer tracheids very small and often obscure. Bor- 

 dered pits round or elliptical in i row, or in radially broad tracheids 

 in 2 rows. Resin cells not numerous, 20-25 /j. wide, 150-175 /x 

 long. 



Tangential. Rays medium, wholly I -seriate ; the cells narrow, oblong. 



Wood very light and soft, but very durable in the soil. 



Relative specific gravity . . . . 0.3322 



Approximate relative fuel value 33-12 



Coefficient of elasticity in kilograms on millimeters . . 404. 



Ultimate transverse strength in kilograms 194. 



Ultimate resistance to longitudinal crushing in kilograms 4149. 



Resistance to indentation to 1.27 mm. in kilograms . . 1074. 

 (Sargent) 



Cape Breton Island and near Halifax (Macoun) ; southern Maine, south- 

 ward along the coast to Florida, thence westward along the Gulf coast 

 to Pearl River, Mississippi (Sargent). 



The Pleistocene deposits of the Don Valley, Toronto. Material not pet- 

 rified, but often showing the effects of advanced decay. 



2. C. Lawsoniana, A. Murr. 



Port Orford Cedar. Oregon Cedar. White Cedar. Lawson's Cypress. 



Ginger Pine 



Transverse. Growth rings very narrow, variable, the structure very open 

 throughout. Summer wood very thin, of 1-5 tracheids, sometimes 

 double and then upwards of 14 tracheids, the transition to the spring 

 wood gradual. Spring tracheids very large, squarish-hexagonal, thin- 

 walled, in very regular rows, uniform. Resin cells prominent, large, 

 usuallj^widely scattering and not numerous, or again numerous within 

 narrow zones in the summer wood. Medullary rays resinous, rather 

 prominent and numerous, i cell wide, distant 1-9 or 12 tracheids. 



Radial. Ray tracheids wholly wanting. The straight or somewhat con- 

 tracted ray cells rather resinous, equal to 3-12 spring tracheids; the 

 upper and lower walls variable, often strongly thickened toward the 

 ends of the cells, not obviously pitted ; the terminal walls thickish, 

 chiefly straight, not pitted or locally thickened ; the lateral walls with 

 small bordered pits with a narrow orifice, 1-4, or more rarely upwards 

 of 8, per tracheid and chiefly in vertical rows. Bordered pits in i 

 row, sometimes in 2 rows, round. Pits on the tangential walls of the 



