CHAPTER IV SPERMATOPHYTES 
Introductory. The Spermatophytes (seed plants) include the most 
highly organized plants, and are distinguished from the lower groups by 
the production of seeds. Once they were called Phanerogams, a name 
contrasted with Cryptogams, which included all the lower groups. 
Phanerogam means " sexual reproduction evident," and cryptogam 
means " sexual reproduction concealed." This distinction was based 
upon the belief that stamens and pistils are sexual organs, and that no 
such organs are evident in the lower groups. In fact, the sexual organs 
are very evident in the groups included under cryptogams; while they 
are very obscure in the so-called phanerogams. 
The seed plants were also generally called flowering plants, but the 
flower is not a structure that defines the group. There are two possible 
definitions of a flower. A very common one is that it is essentially a 
group of sporophylls (stamens and carpels) ; but this definition includes 
the strobilus, a structure well represented among pteridophytes. An- 
other definition of a flower is that it is a structure in which a perianth 
(sepals and petals) is associated with the group of sporophylls; but this 
definition excludes many seed plants, and especially all the gymno- 
sperms. The limit of the flower, therefore, is either more extensive 
than seed plants or less extensive; and since the structure does not fit 
the group, the name flowering plants has been abandoned. The seed 
is a structure that seems to agree exactly with the boundary of the group, 
and therefore the name seed plants (spermatophytes) seems to be the 
most appropriate. 
The two groups of spermatophytes are Gymnos perms and Anglo- 
sperms, the names expressing the conspicuous difference ; for in gymno- 
sperms the seeds are exposed, and in angiosperms they are enclosed in a 
case. This difference is very far from expressing the full contrast be- 
tween these two groups, but the characters will be developed as the groups 
are described. It is sufficient to state here that the gymnosperms are 
very ancient and form a comparatively small part of the present seed 
plant vegetation; while the angiosperms are comparatively modern 
and include the great bulk of the present seed plant vegetation. 
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