S2 ROYAL SOCIETY OF CANADA 



6. Sequoia, Endl. 



Transverse. Growth-rings chiefly narrow, the summer wood distinct but 

 thin. Resin-passages wanting or rarely present, and then imjjer- 

 fectly formed and in compact rows (S. sempervirens). Eesin-cells 

 scattering, chiefly in the spring wood. 



Radial. Eays without tracheids. Ea3"-cells with consjDicuous, oval, nar- 

 rowly bordered pits, the oblong orifice often parallel to the cell axis. 

 Pits sometimes on the tangential walls of both spring and summer 

 woods. Tracheids wholly without spirals. Terminal walls of the 

 ray-cells rarely, if at all, jiitted. 



Tangential. Fusiform rays wholly wanting. Ordinary rays one to two- 

 seriate, the cells broadly oval, chiefly large. 



Species. 



1. S. gigantea, Decaisne. 



2. S. sein2)ervirens. End). 



T. Abies, Link. 



Transverse. Growth-rings usually broad, with no very clear distinction 

 between the spring and summer woods. Eesin -passages rarely pre- 

 sent (^A. nobilis and A. bracteata). Eesin-cells remote and usually 

 obscure on the outer face of the summer wood. 



Madial. Eay tracheids wanting, except in A. balsamea. Parenchyma 

 ray-cells generally straight in the summer wood ; the terminal walls 

 strongly pitted. Tracheids wholly without spirals. 



Tangential. Fusiform rays wholly wanting. 



Species. 



1. A. balsa)nea. Mill. 6. A. magnijica, Murr. 



2. A. Fraseri, Lindi. 7. A. aviabilis, Forb. 



3. A. lasiocarpa. Hook. 8. A. concolor, Lindl. and Gord. 



4. A. hracteatd. Hook, aud Arn. 9. A. grandis, Liudl. 



5. A. nobilis, Liudl. 



8. TsuGA, Carr. 



Transverse. Growth-rings usually thin, the summer wood prominent. 

 Eesin-passages wholly wanting. Eesin-cells usually remote, and often 

 more or less obscure on the outer face of the summer wood. 



Radial. Eay tracheids prominent but n:\rrow. Eaj^-cells generally resin- 

 ous, more orless conspicuously contracted atthe ends, the terminal walls 

 strongly pitted ; the upper and lower walls entire or imperfectly pitted, 

 often thickened at the ends of the cells, so as to make the latter ap- 

 pear strongly contracted. Tracheids wholly without spirals. 



Tangential. Fusiform rays wholly wanting. 



Species. 



1. Ï'. Mertensiana, Carr. 3. T. raroliniana, Engel. 



2. T. canadensis. Carr. 4. T. Pattoniana, Engel. 



