180 PLANT-LIFE 



to geological evidence, pre - eminently modern ; the 

 Gymnosperms are more primitive in every respect. 

 Angiosperms are, far excellence, " flowering " plants. 



There are three classes of Gymnosperms, the Cycads, 

 to which we have already alluded, the Coniferae, and 

 the Gnetales. We dismiss the last-named with a mere 

 mention, as they are hardly known to any but expert 

 botanists. Concerning the Cycads it should be added 

 that the sexes are represented on separate plants. 

 The so-called " Sago-Palm," Cycas revoluta, so fre- 

 quently cultivated in hothouses, is likely to be the 

 most familiar example; it is a native of Asia. The 

 leaves are rolled up in crozier fashion when young, in 

 which respect they resemble those of Ferns. The 

 megasporangia (ovules) are as large as plums. They 

 are borne on leaves very like ordinary foliage leaves. 

 The male plant produces a terminal cone composed of 

 specialized leaves arranged spirally on the axis, and 

 the microsporangia are produced on the backs of these 

 leaves, in great numbers. The Coniferse deserve more 

 than a passing mention. 



The Cone-bearing plants, the Conifers, are conspicu- 

 ous trees or shrubs with woody, much-branched stems. 

 The Class embraces the well-known Pines, Firs, Larches, 

 Cypresses, Junipers, and Yews. They commonly bear 

 needle-like linear, undivided leaves of firm texture 

 which generally endure through several seasons, so 

 that the plants are said to be " evergreen." They 

 abound in temperate regions of the globe and approach 

 the polar areas; when they are found in the tropics, it 

 is usual for them to occur at mountainous elevations. 

 The sexes are represented in separate flowers and some- 



