292 



BOTA.XICAL GAZETTE 



Figs. 71-89. — Thuja occidentalis: figs. 71-81, transverse section of strobilus axis, 

 showing origin of sterile bract bundles (stb, stb') below cone, bract bundles (b-b*) of 

 sporophylls, and scale bundles (s-s<) ; fig. 82, transverse section of same strobilus, many 

 of scale bundles become oriented like bract bundle, two pairs of sporophylls fertile, 

 one pair bearing one ovule per sporophyll, the other two ovules; figs. 83, 84, transverse 

 sections near tip of sporophyll, bract (B) and scale (5) beginning to separate; fig. 85, 

 longitudinal section of sporophyll, bract (B) and scale (S) closely united; figs. 86- 

 89, sections parallel to cone axis; fig. 86, bract (6) and scale (s) bundles distinct in 

 origin in upper part of strobilus, united in lower (bs); figs. 87-89, bract bundle separat- 

 ing from scale bundles; X 16. 



