2(> K Canadian Arctic Expedition, 1913-18 



EXPLANATION OF PLATE III. 



PI.ATK '2. Spruce from Coppermine River forest, below Sandstone rapids. 



Fig. 1. Section showing work of Polygraph us rujifwnnis Ky., beneath the bark. 



Fiji. 2. Spruce branch showing tunnels of Carphoboni* andersoni Sw. 



Fig. '.). Spruce branch showing tunnels of Xylotrcchnx nmlitlaln* and Xcocli/titx tt<ric(itiiln. 



l-'ig. 4. Same as figure :>, the reverse side. 



