178 



Fig. 61. Samples e.xposed I6^i months at the Oakland Mole. No. A19. Oregon alder con- 

 siderably attacked by Limnoria except in areas where bark remained on. Compare area above the 

 white card with smooth area below, where bark was removed just before photographing. No. A20. 

 Douglas fir sample dipped once in "Elaterite." General attack by Limnoria all over surface. No. A21. 

 Douglas fir sample dipped twice in "Elaterite." Heavily attacked by Limnoria. Diameter considerably 

 reduced. 



