312 



HOMER G. TURNER AND H. R. RANDALL 



Fig. 6.— a part of Fig. 5 (Xsoo) showing the 

 great detail revealed by the method of treat- 

 ment described in this paper. Note the deli- 

 cate dumbbell-shaped membrane with the cells 

 and the elliptical markings surrounding the small 

 knots along the cells walls. 



Fig. 7. — Cross section (X83) of a charcoal stem 

 of coniferous wood found in anthracite from coal 

 measures around Minersville, Pennsylvania. Note 

 the weU-defined medullary rays and annual rings. 

 The rather thick cell walls are composed almost en- 

 tirely of bright, jetty material making possible this 

 photograph by reflected light. The black spots 

 within the cell walls are holes. 



Fig. 8. — Section (X118) crosswise to 

 the bedding of coal from the Primrose bed, 

 William Penn colliery. This section 

 through the duller layers shows wood fiber 

 much contorted. 



Fig. 9. — Section (X118) crosswise to 

 the bedding of the Primrose bed show- 

 ing less flattened wood fiber. 



Fig. 10. — Section (X124) crosswise to 

 the bedding, from Pennsylvania Anthra- 

 cite. This section through the duller 

 layers shows a somewhat macerated wood 

 fragment containing round bodies which 

 are probably vessels formerly filled with 

 resin or gum. 



