Branch II— PHYCOPHYTA. 



Uni- or multi-cellular plants; thallus generally filamentous, often 9tratose, simple, or 

 ramose, chlorophyll-green, or colorless; reproduction sexual and asexual; asexual repro 

 duction by means of fission, by zoospores, or by cysts; sexual reproduction by means of 

 isogametes or heterogametes. 



Mostly inhabitants of fresh or sail water. A few are terrestrial, b iwever, and several 

 small families are parasitic or saprophytic. One class, Phaeophyceae, is compo 

 marine algae exclusively, and of course Hints qo representation in the state 



In Protocoecus and related genera the phycophytes represent probably the ni'>-t prim 

 itive forms of plant life. On the other hand, however, this branch stand-- a> ti. 

 central stock from one part of which the long series of parasites and saprophytes have 

 sprung, and from another the red sea -weeds and stone-worts. 



Class II.— CHLOROPHYCEAE. 



Chlorophyll-green or colorless; chlorophyll, when present, disposed in definite bodies 

 (chloroplasts); thallus one or many-celled, simple, branched, or explanate; repro luction 

 sexual and asexual; asexual propagation by the formation of motile spores (zoospores 

 which after a short time come to rest and form new plants, or, in terrestrial parasitic and 

 saprophytic forms, by non motile spores; sexual repro luction by the union of two cells 

 or protoplasts (gametes); gametes either similar (isogametic reproduction), or dissimilar 

 (heterogametic reproduction |. 



SYNOPSIS. 



Order. — Protoooeooideae. — Unicellular or multicellular, chlorophyll-green "i- color 

 less; cells free, aggregated or segrega ted into families; propagation by 

 means of zoospores; reproduction by copulation of microzoospores 



Order.— Conjugatae.— Unicellular or filamentous, chlorophyll-green or col 



propagation by cell division; reproduction by the conjugation of two aim 

 ilar cells ^isogametic). 



Order. — Siphoneae. — Apparently unicellular, consisting of elongab in one 



family), occasionally branching, plurinucleate, chlorophyll green or ••■d<>r 

 less filaments; propagation by zoospores; reproduction usually bet 

 gametic. 



Order.— Confervoideat'. -Thallus many celled, filiform or rarely membramv us, 



always chlorophyll-green; cells uniseriate, forming simple or branched 

 filaments, or pluriseriate, forming a membranaceous stratum; pro] 

 tion by zoospores; reproduction either isogametic, heterog 

 wanting. 



Order .'{.-IMtOi (U <K ( Ol l>KA ■■:.- Chlorophyll green or colorless, usually micro 



scopic, wit hunt ramification or terminal growth; cells single, solita 

 aggregated into families; propagation by cell division, neutral zoogonidia, 

 or rarely by granules; reproduction isogametic. 



