DIVISION IL 

 GYMNOSPERMS. 



CHAPTER XIX. 



CONIFERAE: THE SCOTS PINE. 



So far the description which has been given has related to the Angio- 

 sperms, in which the ovules are protected by a carpellary wall, and 

 the pollen-grain is received upon a stigmatic surface. These Plants 

 appeared relatively late in Geological Time. Their records date back 

 only to the Cretaceous Period. Comparative evidence supports the 

 conclusion that they are the culminating types of Vegetation, and 

 rightly occupy the highest position. Their ready adaptibility to 

 their surroundings has led to their success in the struggle for existence, 

 as shown by the profusion of their forms now living. In fact, they are 

 the dominant types of the Present Day. 



But Seed-Plants of a more primitive type long ante-dated the 

 Angiosperms. Seeds existed in the Devonian Period. They belonged 

 to forms corresponding more nearly to those living Plants which are 

 collectively named Gymnosperms, than to the Angiosperms. This 

 gives a special interest to the study of the living representatives of 

 the Gymnosperms, a class which have as their leading characteristic 

 the free exposure of their seeds, a carpellary protection being absent. 

 The leading family of living Gymnosperms is the Coniferae, so named 

 from the fruiting body with its hard woody scales, well exemplified 

 by the ordinary Fir-Cone. Vast forests of such Conifers exist in 

 temperate and sub-arctic zones. These are the sources of the : upply 

 of soft-wood, turpentine and pitch. 



In the British Flora the Gymnosperms are represented only by 

 Coniferae, such as Scots Pine (Pinus sylvestris), the Yew (Taxus baccata), 



302 



