PLATK XXIV.— RADIAL AND TANGENTIAL SECTIONS. 



-( iind /;, PiNiis T.KUA. Kadial seotious; hi. r., incdiUlary rayH; tr., traclieids; p.. iiaroiichyiiia i>t' tlic rays; s. ;)., 



simple pit; b. i>., bordered pit; c. tr., comnuiii Iracheids. 

 C-E, taugcutial sections. 



C, Pixus I'ALUSTias. Lelt-baiiil part in springwood, rij;bt-haud jiortiiin in .sMniinernond. 



D-E, PiNUS ECIIINATA. D, Soctioii in springwood ; a-c, inednllary rays; o, a small ray composi^d <if traeheids only; 

 c, a " triple" ray ; d, bordered pit sbowing the membrane in place. K, Section in summerwood ; a. bordered 

 pit, other letters as in // and /;. 

 Magnification of originals, *','"; <>f illustrations: A and /!, -f"; C-E, ^'i^. 

 150 



