VI INTRODUCTION. 



and cones also differ essentially in the different Genera. In that 

 of PiNUS (the true Pines) the leaves are long, slender, and in 

 bundles of twos, threes, or fives, each set being enclosed at the 

 base in a scaly sheath, and with the fruit a cone, composed of 

 persistent scales. In the Genus Abies (the Spruces) the leaves 

 are solitary, more or less scattered round the shoots, or some- 

 what two-ranked in their direction, as in the Hemlock Spruce, 

 and with the cones in a drooping position, and composed of per- 

 sistent scales. In the Genus Picea (the Silver Firs) the leaves 

 are flattened, linear, or lanceolate, white beneath, and mostly 

 arranged on the upper side of the shoots, in a more or less pec- 

 tinated manner ; the cones are erect on the upper side of the 

 top branches, and composed of deciduous scales, which fall off 

 the axis when the seeds are ripe. In the Genus Larix (the 

 Larches) the leaves are linear, soft, rounded at the points, deci- 

 duous, and disposed in groups on the adult parts of the tree ; 

 the cones are small, erect on the upper side of the branchlets, 

 and composed of loosely-placed persistent scales. In the Genus 

 PsErDOLARix (the Chinese Larch) the leaves are long, linear, 

 soft, deciduous, and disposed in tufts, or bundles, on the adult 

 branchlets, and with the cones rather large, pendulous, and 

 composed of very deciduous and divergent scales. In the 

 Genus Cedkus (the Cedars) the leaves are in tufts on the adult 

 parts, persistent and evergreen; with the cones erect on the 

 upper surface of the larger branches, and the scales more or 

 less deciduous after the seeds are ripe. From the true Abietinae 

 Professor Link has, in a very able article on the Genus Pinus, 

 separated the Genera, comprising Dammara, Cunninghamia, and 



