NOTES ON WEST AMERICAN CONIFERS. 161 



by the enlargement of tlie tree, while the cones are held cap- 

 tive in the bark and carried outward during the life of the 

 tree. No pine exceeds this species in the persistence of its 

 cones, except its close relative, of locations a little farther 

 inland, the Knob-Cone Pine, Pinus attenuaia, Lemmon, the 

 cones of which often remain closed as well as persistent 

 during the life of the tree— and sometimes they are found 

 imbedded within the trunk. 



As Bolander reported, the trees of Mendocino closely 



Monterey 



Don., in the 



particulars mentioned, but the bark is relatively much thicker 

 than in that species, trees but eighteen inches in diameter show- 

 ing bark four to six inches thick and cleft into blocks, or into 

 long wings resembling those on branches of Cork Elm. As 

 might be expected, trees in rich loam of the coast bear larger 

 cones and leaves (these of a greener cast) than those of the 

 interior, but all are supplied with abundance of pitch or 

 resin; the bands of dark, hard, small summer cells— seen in 

 a cross-section of the tree— occupy about one-fourth of the 

 annual layer of these usually rapidly growing trees, one- 

 half to one inch layers being a common occurrence. 



Before leaving this fine representative of the four 

 crouching, fighting, and conquering pines of our western 

 shores, it will be interesting to notice certain peculiarities of 

 each of them, since their differences form a gradual scale of 

 development of the cones and leaves. 



Beginning at the north we find on the Alaska islands, and 

 occupying the flat beaches and promontories almost contin- 

 uously for fifteen hundred miles to Mendocino, the little 

 Nortli Coast Pine, Pinus contoria, Dough, with cones barely 

 an inch long and three-eighths of an inch wide on the bleak, 

 inhospitable islands— increasing t« two or three inches long 

 on the Mendocino coast— and with leaves in pairs, at first but 

 about an inch long, increasing to two inches in the southern 

 representatives of the species. This pine overlaps the terri- 

 tory of its robust neighbor, the Prickle-Cone Pine, Pinus 

 miiricaia, Don., we have just been considering, which has 



