192 PHYLUM IV. SIPHONOPHYCEAE 
sexual organs, and are to be regarded as mere vestiges of 
the fully developed antherids and oogones of the Green 
Felts. ‘They are sexual organs on the road to extinction. 
In the Insect Fungi the sexual organs are still more de- 
generated and vestigial in structure. 
288. The commonest example of the Higher Tube 
Algae is the little Bladder Alga (Botrydium), found on 
moist ground. It is a globular coenocyte 
. a millimeter or two in diameter, with a 
‘branching root below. When in good 
‘‘ vegetative condition it is bright green, but 
later it may be dull red. It is known to 
Fic, 92. Propagate by uniciliated zoospores, and 
pane thick walled chlamydospores. Its genera- 
tion was long supposed to be by the union 
of biciliated isogametes, but these are now thought to 
belong to Protosiphon, a similar plant with an unbranched 
root. 
289. In the shallow waters of the ocean there are 
larger Bladder Algae (Valonia) that when young are 
single globose or club-shaped coenocytes, firmly rooted 
below. ‘They may reach several centimeters in height, 
and ultimately become more or less divided 
into segments. Their propagation and 
generation appear to be much like that 
of the little Bladder Algae. 
290. The Sea Ferns (Bryopsis) are erect, 
slender, cylindrical, single coenocytes, rooted Il. 
below, and pinnately branched above, and ria. 83.—Bry- 
look like little trees, or fern-leaves. They ore ae 
generate by biciliated heterogametes. They 
occur along the shores of the warmer oceans. 
291. The pretty Sea Umbrellas (Acetabularia) are 
also erect, slender, cylindrical, single coenocytes, rooted 
