PBANEBOGAMIA. 235 



gigantea), and grows in a few valleys on the western slope of the 

 Sierra Nevada Mountains in California. It attains a height of more 

 than 100 metres (300 feet) and a diameter of 6 to 10 metres (20 to 

 30 feet). The other species is the common Redwood (8. semper- 

 virens), confined to the coast-range mountains of California. It is 

 but little inferior to the preceding in size, and its wood is extensively 

 used for building and other purposes. 



In the Southern Hemisphere the Kauri pine (Agathis australis) of 

 New Zealand, tlie Norfolk Island pine (Araucaria excelsa) of the 

 South Pacific Ocean, and others represent a group of conifers closely 

 related to those which were abundant in ancient geological times. 



476. The Joint-Firs {Order Gnetacece) include a few 

 undershrubs or small trees, mostly natives of the warmer 

 parts of the world. Their curious structure is far too diffi- 

 cult to be taken up here. 



Class IT. Angiospeem^ {the Angiosperms). 



4'76. The plants of this class have, in most cases, more 

 or less elongated stems; these are solid at first, and in the 

 great majority of cases they remain so. They usually bear 

 ample leaves, with parallel or netted veins. 



47'7. Their reproductive organs are mostly collected into 

 definite and distinct flowers, which often show great beauty 

 of form and color. The pollen-bearing leaves (stamens) 

 resemble those of the Gymnosperms, but the ovule-bearing 

 leaves (carpophylls) are folded into a closed vessel (ovary). 



478. Most Angiosperms are terrestrial and chlorophyll- 

 bearing plants; there are, however, many aquatic and aerial 

 species and a considerable number of parasites. They 

 range, also, in size and duration, from minute annuals, a 

 millimetre in extent, to enormous trees, 50 to 150 metres 

 high and many centuries old. 



479. We have seen (pp. 216-218) that in the Gymnosperms 

 the flower consists of a stem upon which are the leaves 



