DIVISION V. 



SEED-PLANTS.— G YMNOSPERMS. 



CHAPTER XXXIII. 



CONIFERAE: THE SCOTS PINE. 



The description already given in Chapters I. to XIX. has presented 

 the structure and development of the Higher Flowering Plants, or 

 Angiosperms, 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 adaptability to 

 their surroundings has contributed 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 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 GytntUh 

 sperms, 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. Being simpler in their propagative 

 methods, as they are also in certain structural features, and having 

 existed in earlier geological periods than the Angiosperms, they are 

 naturally held as the more primitive Seed-Plants, and as such they 

 may be expected to offer features valuable for comparison with the 

 Pteridophyta. This is found to be the case, and it is this which makes 

 the study of them of special value. 



5^5 



