300 The Conifers. 



the western coast of North America, they form the principal and 

 often the only trees over wide areas. 



1233. Their wood, under the microscope, shows an abundance 

 of bordered pits [ 256], by which the smallest fragment may be 

 identified, even in the fossil form. The sexes of the blossoms are 

 separate, on the same or on different trees ; they have no floral en- 

 velopes, and their pollen is provided with an arrangement that ren- 

 ders it buoyant, so as to be carried unusual distances in the winds. 

 The ovules or young seeds have no pericarps, and are fertilized by 

 direct contact of the pollen, without either stigma or style, and for 

 this reason they are called gymnosperms. 1 The seeds contain several 

 cotyledons [ 132], instead of one, as in endogenous plants, or a 

 pair, as in most of the species noticed in the preceding pages, and 

 from this they are also called polycotyledonous. The number is 

 usually from six to ten, and hence the germinating seed presents 

 leaves of corresponding numbers. 



1234. The seeds of this order are usually placed between hard, 

 woody scales, arranged spirally and regularly around an axis, form- 

 ing, until ripe, a, solid conical or ovoid mass, and they are in many 

 species provided with a wing that enables them to be wafted by the 

 winds, when they are liberated by the opening of the scales. The 

 structure of the blossoms and seeds of one of the most important 

 of the genera in this order may be seen in the annexed engraving. 



1235. In some cases, the cones that bear the seed can scarcely 

 be recognized. The scales become pulpy and the fruit berry-like ; 

 in many species there is no trace of a wing to the seed, and the 

 fruit may be solid and nut-like. Sometimes the seeds are large and 

 edible. In the structure of the cone, and otherwise, the coniferse 

 present analogies to the higher lycopods or club-mosses, and to the 

 vegetation that prevailed in the carboniferous period, the remains 

 of which form the bulk of our mineral coal. 



1236. In most of the conifers we find resiuiferous cells in the 

 wood of the trunk, branches, and roots, the bark, and sometimes, as 

 in the pines, in the leaves. [ 793.] The leaves in transverse sec- 

 tions present a cellular structure, very uniform in the different spe- 

 cies, and affording characters upon which a classification has been 

 based. We see an example of this in Fig. 20 of the accompanying 

 engraving. 



*A term from tho Greek, signifying " miked seeds." 



