246 ANATOMY OF THE GYMNOSPERMS 



1. * J. virginiana, Linn. 



Red Cedar. Savin 



Transverse. Growth rings usually broad, often double or treble. The thin 

 summer wood rather open and passing gradually into the broad spring 

 wood. Spring wood rather open, the tracheids variable with medium 

 walls, in regular rows. Resin cells rather small and usually disposed 

 in 1-2 open bands chiefly in the spring wood. Medullary rays not 

 very prominent or resinous, rather numerous, i cell wide, distant 

 2-13 tracheids. 



Radial. Ray cells not very resinous, equal to 5-10 spring tracheids; the 

 upper and lower walls rather thick, unequal and remotely pitted ; 

 the terminal walls thin, straight, and entire, rarely curved or locally 

 thickened ; the lateral walls with small, chiefly bordered pits 6 /j. 

 broad, chiefly 2, more rarely 4, per tracheid, the orifice narrow, 

 linear-oblong. Bordered pits round, in I row, sometimes in pairs, 

 the orifice rather large. Pits on the tangential walls of the summer 

 tracheids numerous, flat. Resin cells about 20 /j. broad, 100150 p. 

 long. 



Tangential. Rays sometimes 2-seriate in part, low ; the cells small, nar- 

 rowly oval to round, chiefly round, thick-walled, resinous. 



A tree 20-30 m. high, with a trunk .60-1.35 m. in diameter. Wood light, 

 soft, not strong, brittle, very close and straight grained, compact, easily 

 worked, very durable in contact with the soil, odorous. 



Relative specific gravity 0.4926 



Approximate relative fuel value 49. u 



Coefficient of elasticity in kilograms on millimeters . . 670. 



Ultimate transverse strength in kilograms 316. 



Ultimate resistance to longitudinal crushing in kilograms 6750. 



Resistance to indentation to 1.27 mm. in kilograms . . . 2376. 

 (Sargent) 



Nova Scotia ; uncommon about Ottawa, but becoming more common 

 westward throughout Ontario, abundant at Bay of Quinte, thence south- 

 ward, crossing the St. Lawrence River midway between Montreal and 

 Lake Ontario (Macoun); southward from New Brunswick to Tampa 

 Bay, Florida ; westward through Texas, Nebraska, Kansas, and Okla- 

 homa to the looth parallel, thence north to northern Michigan, Wiscon- 

 sin, and Minnesota ; in the Pacific region through the mountains of 

 Colorado and British Columbia to Vancouver Island (Sargent). 



Pleistocene of the Don Valley, Toronto. 



Material not petrified, but remarkably well preserved in its natural state, 

 and exhibiting the characteristic odor when cut. 



