PLATE LIT. 
Fig. 6. Showing the position of the male when he ‘is just starting 
his burrow through the outer bark. Magnified 12 dia. 
Fig. 7. Position several hours later. The spines upon the dorsum 
of his prothorax are pressed against the bark on one side of the burrow 
serving to anchor his body while the mandibles work upon the other 
side. Magnified 12 dia. 
Fig. 8. Showing the shape of the burrow when about half of the 
‘body is covered. As soon as the outer bark is burrowed through, the 
burrow is widened slightly and carried downward at an angle. Magnified 
12 dia. 
Fig. 9. Male in position in the burrow with about two-thirds of his 
body covered. Magnified 12 dia. 
Figs. 10 and 11. Showing male at work in his burrow, which is now 
being extended parallel with the surface of the bark. The beetle works 
as readily in the position shown in Fig. 11 as that shown in Fig. 10. 
It is necessary that he constantly shift his position in order to bring 
the mandibles into play on all sides of the burrow. Magnified 12 dia. 
Fig. 12. If the male is disturbed while working in position shown 
in Fig. 11 he will back up to the entrance in the manner shown here, 
but immediately rotates and takes the position shown in Fig. 13. 
Magnified 12 dia. 
Fig. 13. The “guarding position” assumed by the male when dis- 
turbed in any manner. In this way the opening into the burrow is 
effectively closed against intruders. 
