SPERMATOPHYTES : GYMNOSPEEMS 345 
arising from the fact that what were supposed to be sexual 
organs in Phanerogams have proved not to be such. The 
name Phanerogam, therefore, is being generally abandoned ; 
but the name Cryptogam is a useful one when the lower 
groups are to be referred to ; and the Pteridophytes are 
still very frequently called the Vascular Cryptogams. The 
most distinguishing mark of the group seems to be the 
production of seeds, and hence the name Spermatophytes, 
or " Seed-plants," is coming into general use. 
The seed can be better defined after its development 
has been described, but it results from the fact that in this 
group the single megaspore is never discharged from its 
megasporangium, but germinates just where it is devel- 
oped. The great fact connected with the group, therefore, 
is the retention of the megaspore, which results in a seed. 
The full meaning of this will appear later. 
There are two very independent lines of Seed-plants, 
the Gymnosperms and the Angiosperms. The first name 
means "naked seeds," referring to the fact that the seeds 
are always exposed ; the second means " inclosed seeds," 
as the seeds are inclosed in a seed vessel. 
GYMNOSPERMS 
225. General characters. The most familiar Gymnosperms 
in temperate regions are the pines, spruces, hemlocks, 
cedars, etc., the group so commonly called "evergreens." 
It is an ancient tree group, for its representatives were 
associated with the giant club-mosses and horsetails in 
the forest vegetation of the Coal-measures. Only about 
four hundred species exist to-day as a remnant of its for- 
mer display, although the pines still form extensive forests. 
The group is so diversified in its structure that all forms 
can not be included in a single description. The common 
pine (Pinus), therefore, will be taken as a type, to show 
the general Gymnosperm character. 
