CHAPTER XIV. 



SUB-KINGDOM VI. 

 SPERMAPHYTES : PH^ENOGAMS. 



THE last and highest great division of the vegetable king- 

 dom has been named Spermaphyta, " seed plants," from the fact 

 that the structures known as seeds are peculiar to them. They 

 are also commonly called flowering plants, though this name 

 might be also appropriately given to certain of the higher 

 pteridophytes. 



In the seed plants the macrosporangia remain attached to 

 the parent plant, in nearly all cases, until the archegonia are 

 fertilized and the embryo plant formed. The outer walls of 

 the sporangium now become hard, and the whole falls off as 

 a seed. 



In the higher spermaphytes the spore-bearing leaves (sporo- 

 phylls) become much modified, and receive special names, 

 those bearing the microspores being commonly known as sta- 

 mens ; those bearing the macrospores, carpels or carpophylls. 

 The macrosporangia are also ordinarily known as " ovules," a 

 name given before it was known that these were the same as 

 the macrosporangia of the higher pteridophytes. 



In addition to the spore-bearing leaves, those surrounding 

 them may be much changed in form and brilliantly colored, 

 forming, with the enclosed sporophylls, the "flower" of the 

 higher spermaphytes. 



As might be expected, the tissues of the higher sperma- 

 phytes are the most highly developed of all plants, though 



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