PLATE XXII. 



A, PlNUS ECHINATA. Cross section of two rings; sp. w., springwood; ««. ic, suinnierwood. 



Jl, PlNUS I'ALUSTr.ls. Cross section of a very narrow ring. Of the two mediillarv rays one is <nt tlironj;Ii a row of 



parenchyma, the other through a row of tracheids. 

 C and I), PiNus Gl.Aiiit.v. Kadial sections; m. r., iu(dnl;ary rays; (r., tracheids of the nieilullaiy rays; p.. parencliyiiia 

 of the same; s.p., simple pits leading from the parenchyma to the neiglilioriiig tracheids or common liliers 

 c. Ir.; b.p., hordered pit. The ray at (' is made up of tracheids only. 

 Ji, Pints I'ALrsxRi.s. Kadial section; lettering as in ]>. 



Originals magnified: J, ^'1", the rest ^y^; illustrations: A, ","', the rest •1''. 

 UG 



