186 PHYLUM IV. SIPHONOPHYCEAE 
spore eventually forms a wall around itself, and then 
proceeds to elongate into a new plant-body. 
271. Generation takes place in special, usually lateral, 
segments. Both antherids and oogones develop as pro- 
tuberances upon the stem. The antherid is long and 
rather narrow, and soon much curved; its upper portion 
becomes cut off by a partition, and in it very small bi- 
ciliated sperms are developed in great numbers. ‘The 
oogone is short and ovoid in outline, and usually stands 
near the antherids. In it a partition forms at its base; 
the upper portion becomes an oogone, and its protoplasm 
condenses into a rounded body, the egg. At this time 
the wall of the oogone opens, and permits the entrance of 
the sperms which were set free by the rupture of the 
antherid wall. : 
272. Upon coming into contact with the egg one sperm 
fuses with it; the fertilized egg (zygote) immediately 
begins to secrete a wall of cellulose about itself, and it 
thus becomes a resting spore. After a period of rest the 
thick wall of the resting spore splits, and through the 
opening a tube grows out which eventually assumes the 
form and dimensions of the full-grown plant. 
Here must be placed half a dozen families of hystero- 
phytic plants, the ‘‘Tube Fungi,” often known as the 
“lower fungi,’’ and to be regarded as degen- 
} f erate descendants of some such holophytic 
form as Vaucheria. 
273. The Water-molds (Saprolegniaceae) 
are colorless saprophytes or parasites. They 
are generally to be found in the water, 
Pda LER attached to the bodies of living or dead 
fishes, crayfishes, etc., or in decaying animal 
or vegetable matter, in or out of the water. The plant- 
body is greatly elongated and much branched, and is 
