CHAPTER XXI 
THE SPERMATOPHYTES 
This is the highest evolved division of the vegetable kingdom. 
It includes all plants which produce real flowers and seeds. The 
older name for the group is Phanerogamia. In this group the 
sporophyte attains its greatest development while the gameto- 
phytes are reduced to minute structures parasitic on the sporo- 
phyte. The Spermatophytes are subdivided into two subdivi- 
sions based primarily upon whether their seeds are borne naked 
or enclosed within a seed vessel or pericarp. — 
Subdivision I. Gymnospermz (Gymnosperms)—plants with 
naked seeds. _ 
Subdivision II. Angiospermae (Angiosperms)—plants with 
covered seeds. ao 
THE GYMNOSPERMS 
The Gymnosperms comprise an ancient and historic group of 
seed plants which were more numerous in the Triassic and Car- 
boniferous periods than now. They differ from the Angiosperms 
in several respects, viz.: they bear naked ovules on the edges or 
flat surfaces of leaves called carpels, while Angiosperms bear 
covered ones; each ich_megaspore_ produces within itself a bulky 
prothallus, in the upper portion of which originate one or more 
archegonia, while in Angiosperms no recognizable prothallus has 
been proven to exist; the stored food. tissue within their seeds is 
prothallial tissue loaded with starch, etc., while that in Angio- 
sperm seeds (endosperm) is developed from the endosperm 
nucleus; the mode of growth of their stems is always indefinite 
while that of Angiosperms is either indefinite or definite. 
The groups still extant are the Cycads or Fern Palms, the 
Gnetums, the Ephedras, the Ginkgos and the Conifers. Of 
these the Conifers comprising over 300 species are the most 
numerous. Many of them yield valuable products to pharmacy 
and the arts. 
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