276 Field, Forest, and Wayside Flowers 



the needles issuing from the bud we have observed 

 one of the characteristics by which we may deter- 

 mine its species. 



After the leaf-cluster is mature the little brown 

 bud-scales which sheltered its youth drop away and 

 fall. A slow, gentle shower of them drips earth- 

 ward in the pine-woods all through the latter year, 

 and adds largely to that soft, mouldering carpet 

 which covers the ground beneath the trees. 



In the balsam-fir and in the yew-tree each needle 

 has its own guardian scale-leaf, and the foliage is 

 distributed evenly over the surface of the bough 



(Fig. 77). 



Within the needle-like leaves of the pines and 

 their cousins there is no delicate network of 

 branching-veins such as we see in the foliage of 

 oaks and maples. Instead, there is one compact 

 bundle of vessels and tubes, through which plant- 

 fluids creep out toward the sunlight to be 

 digested, and then back again to growing roots and 

 shoots. This bundle lies at the very centre of the 

 leaf, and is sheathed, and in a measure protected 

 from cold by an enclosing tube of thick cells with 

 corky walls. Outside this corky tube lies the 

 green substance of the leaf, composed of delicate 

 cells containing chlorophyll. 



