SUPPLEMENT ITI. 



MICROSCOPICAL EXAMINATION OF WOOD FROM THE 

 BURIED FOREST, MUIR INLET, ALASKA. 



FRANCIS H. HERRICK, PH. D. 



The wood which I examined at the request of 1113' friend, Mr 

 Reid, is in a reniarkabl}^ perfect state of preservation. \\"eath- 

 ered portions are somewhat decomposed at the surface and show 

 traces of wood-borers, Init the deeper parts are perfectly sound. 

 The w^ood is of medium weight, fine grained or of medium grain, 

 and compact. It is odorless and light brown in color, the grain 

 lieing noticeably l)rownish. This color is due principall}' to a 

 brown, or slightly reddish-brown, homogeneous deposit in the 

 cells of the medullary rays. As no portions of the l^ark were 

 obtained, I can speak of the structure of the wood onl3\ This is 

 illustrated liy two drawings (figures 4 and 5) of thin sections made 

 in longitudinal, vertical (tangential to the medullary rays), and 

 transverse planes respectively.* 



Two elements only are met Avith in the wood, namely, trache- 

 ides, or wood-fibers, and the parenchyma of the medullary rays. 

 The tracheides are characterized by the presence of bordered 

 pits on their walls, a common mark of the wood of conifera:^. 

 The outer border of the pit is about ttL mm in diameter, and 

 the inner border or aperture is -3^ mm. The aperture of the 

 canal leading from the cavity of the pit to that of the fiber is 

 frequently slit-like (figure 4, a p), and in the preparations this slit 

 is all that can be seen, in most cases, when the fibers are viewed 

 en face. The outer border of the pit can, however, l)e distinctly 

 seen in exceptional cases. The pits shown in figures 4 and 5 

 were introduced from another part of the section. The dotted 

 lines in the adjoining fiber show the probable outlines of the pits 

 in that cell. The two openings of the pit cavity are shown 

 where the slits apparently intersect. The cavity of the pit is 



* Before sectioning the wood was 'soaked for. about a month in glycerine. 



n— Nat. Geor. Mac, vor,. IV, ^mi. (T.'i) 



