EXOGENOUS OR DICOTYLEDONOUS PLANTS. 



479 



Subclass 2. Gymnospermous Exogenous Plants. 



Ovules, and consequently the seeds, naked, that is, not enclosed in 

 an ovaiy (560) ; the carpel being represented either by an open 

 scale, as in Pines ; or by a more evident leaf, as in Cycas ; or else 

 wanting altogether, as in the Yew. 



922. Ord. ConifcrO! (Pine Family). Trees or shrubs, with branch- 

 ing trunks, abounding in resinous juice (the wood chiefly consisting 

 of a tissue somewhat intermediate between ordinary woody iibre 

 and vessels, and marked with circular disks) ; the leaves mostly- 



evergreen, scattered or fascicled, usually rigid and needle-shaped or 



FIG. 1180. Carpellary scale of Cupressus sempervirens (the true Cypress), seen from with- 

 in, and showing the numerous orthotropous ovules that stand on its base 1181. Branch of 

 Abies Canadensis (Hemlock Spruce) with lateral staminate flowers, and a fertile strobile. 

 1182. Staminate anient, magnified. 1183 Carpellary scale of a fertile ament, with its bract. 

 1184, Similar fertile scale, more magnified and seen from within ; showing the two ovules ad- 

 herent to its base: one of them (the left) laid open. 11S5. The scale in front, nearly of the 

 natural size, its iuner surface occupied by the two seeds. 1186. Poljcotyledonous embryos of 

 Abies and Cypress. 1187. Vertical section of an embryo. 1188. Strobile of Taxodium di»- 

 tichum (Suborder Cupressinete). 



