344 
PLANT STUDIES 
serve to distinguish the four great groups of plants. It 
must not be supposed that these are the only characters, 
or even the most important ones in every case, but they 
are convenient for our purpose. Two characters are given 
for each of the first three groups one a positive character 
which belongs to it, the other a negative character which 
distinguishes it from the group above, and becomes the 
positive character of that group. 
(1) TJiallopliytes. Thallus body, but no archegonia. 
(2) Bryophytes. Archegonia, but no vascular system. 
(3) Pteridophytes. Vascular system, but no seeds. 
(4) Spermatophytes. Seeds. 
224. General characters of Spermatophytes. This is the 
greatest group of plants in rank and in display. So con- 
spicuous are they, and so much do they enter into our 
experience, that they have often been studied as " botany," 
to the exclusion of the other groups. The lower groups 
are not meiely necessary to fill out any general view of the 
plant kingdom, but they are absolutely essential to an 
understanding of the structures of the highest group. 
This great dominant group has received a variety of 
names. Sometimes they are called Anthophytes, meaning 
''Flowering plants," with the idea that they are distin- 
guished by the production of "flowers." A flower is diffi- 
cult to define, but in the popular sense all Spermatophytes 
do not produce flowers, while in another sense the strobilus 
of Pteridophytes is a flower. Hence the flower does not 
accurately limit the group, and the name Anthophytes is 
not in general use. Much more commonly the group is 
called Phanerogams (sometimes corrupted into Phaenogams 
or even Phenogams), meaning " evident sexual reproduc- 
tion." At the time this name was proposed all the other 
groups were called Cryptogams, meaning "hidden sexual 
reproduction." It is a curious fact that the names ought 
to have been reversed, for sexual reproduction is much more 
evident in Cryptogams than in Phanerogams, the mistake 
