-------------------------------------------------------------------- GAMETOPHYTE. (Becoming smaller, mostly independent. In selaginella and isoetes becoming dependent on the sporophyte.) ---------------+-----------------------+---------------------------- | Vegetative Part. | Sexual Organs. ---------------+-----------------------+ Ferns. |A green, thin, | Usually both kinds on (Polypodiaceæ.)|expanded, | the same prothallium. |heart-shaped growth, +---------------+------------ |with rhizoids. |Antheridia with|Archegonia, | |spermatozoids. |each with | | |egg. ----------------+-----------------------+---------------+------------ Equisetum. |A green, thin, | Usually the two kinds |expanded, | on different prothallia. |lobed growth, +---------------+------------ ||with rhizoids. |Antheridia, on |Archegonia | |small male |on larger | |prothallia, |female | |with |prothallia, | |spermatozoids. |each with | | |an egg. ---------------+-----------------------+---------------+------------ Isoetes. |Colorless, rounded | |mass of cells, | |inside of spore wall, | |usually no rhizoids, | On different prothallia. |or but few. Two kinds. | +-----------+-----------+---------------+------------ |Small ones,|Large ones,|One |Few |male. |female. |antheridium, |archegonia, |Developed |Developed |much larger |in apex |into small |from |than the |of oval, |prothallial|nutriment |single |colorless, |cell, and |stored in |prothallial |female |antherid |macrospore |cell. |prothallium, |cell while |from |Antheridium |each with |still in |sporophyte.|with |egg. |sporangium.| |spermatozoids. | ---------------+-----------+-----------+---------------+------------ Selaginella. |Colorless, rounded | |mass of cells inside | |of spore wall, no | |rhizoids, or but few. | On different prothallia. |Two kinds. | +-----------+-----------+---------------+------------