-----------+------------------------+-------------+----------- | GAMETOPHYTE. | | | (Bears the sexual | | | organs and gonidia.) | SPOROPHYTE |How Veg. -----------+------------------------+ Bears |Phase of | Sexual Reproduction. | spores |Gametophyte +------------------------+-------------+ is | Gametes. | Fruit. |Developed. -----------+------------------------+-------------+----------- Spirogyra. | Undifferentiated. | Zygospore |Develops | Entire contents of | Rests. |veg. phase | conjugating cell. | |directly. -----------+------------------------+-------------+----------- | Differentiated. | Egg (or |Develops |Small | Large | oospore). |veg. phase Vaucheria. |two-ciliated | egg | Rests. |directly. |spermatozoids.| cell. | | -----------+--------------+---------+-------------+----------- | Differentiated. | Egg (or |Divides |Oval | Large | oospore). |into Œdogonium. |spermatozoids | egg | Rests. |four cells; |with | cell. | |each |crown of | | |forms |cilia. | | |zoospore |Two from each | | |which |antheridium. | | |develops | | | |veg. phase | | | |again. -----------+--------------+---------+-------------+----------- Coleochæte.| Differentiated. |Egg |Each forms |Oval, | Large |(surrounded |a zoospore. |biciliate | egg |by |Zoospore |spermatozoid, | cell. |wall from |develops |one from each | |gametophyte).|veg. phase |antheridium. | |Rests. |again. | | |Divides | | | |and | | | |grows to | | | |form a mass | | | |of cells. | -----------+--------------+---------+-------------+----------- CHAPTER XVIII. CLASSIFICATION AND ADDITIONAL STUDIES OF THE ALGÆ.