20 



THE CONIFERS OF THE NORTHERN ROCKIES. 



flowers, so called, also possess a central axis, though in this case there 

 are two series of lateral members instead of one. One series is called 

 the scales; these bear the potential seeds upon their upper surfaces, 

 and later form the principal material of the cone. The other series 



FIG. 8. Limber I'ine. On an exposed ridge east of the Divide. 



is known as the bracts, one of which is situated below each scale.. 

 In the earlier condition of the cone the bracts are usually conspicu- 

 ous and surpass the scales, but later the scales outgrow the bracts and 

 in the majority of cases conceal them. 



