Nos. 451-452.] ^A^-'^m'^/J^ OF THE COXIFER. l I.I-.S. 



gates the component cells are far less 

 resin cells of the same section. 

 The parcnch\ ma tracheids are not 

 clearly distin<;uishable from the 

 associated wood tracheids. In 

 radial section the cells are seen to 

 be very variable, thick-walled and 



onger than broad, but opposite the 



rays they 



thev 



cylindrical and 



into ray elements and thus to con- 

 to their primary direction. A care- 

 ful comparison of these cell aggre- 

 gates with those of Sequoia and 

 Abies leaves little room for doubt 



identity, and we cannot do other- 

 wise than conclude that they repre- 

 sent the most primitive structural 

 condition which is capable of di- 

 rectly giving rise to definite cysts 

 by central cleavage. 



tory reservoirs are disposed like section of a resin cyst siiowing the epithe- 

 those of Sequoia, on the outer face p^™(j*filf'te*cyJl!''l^^^ 



of the summer wood, where they are resinous. This figure corresponds to 



form tangential series. They ex- ^ 

 hibit all the gradations from simple cell aggregates without a 

 central space to perfectly formed cysts with a definite epithe- 

 lium. This latter is in one, more rarely in two rows, and it is 

 composed of more or less rounded or radially flattened elements. 

 The parenchyma tracheids are few in number, and the)- are not 

 readily distinguishable from the adjacent wood tracheids. In 



