108 REPRESENTATIVE PLANTS 



2. A portion of a filament (hj)). 



3. Germinating zoospores (Ip). 

 ■4. Rhizoids (Ijy). 



5. Different stages in the formation of antheridia, oogonia, 

 and oospores (I})). 



Observations in conclusion. Observe, by feeling, the rough- 

 ness of this alga as c*omi)ared to spirogyra, hence its com- 

 mon name, " green felt." Observe the numerous small 

 animals that swim about among the filaments comparable 

 to wild animals in a forest. These are of many kinds^ the 

 lowest forms of animal life (infusoria, etc.). Of what ad- 

 vantage to the animals may this growth of algae be ? 



Plants with filamentous plant body, many nuclei, but 

 Avithout apparent cross partitions are called Cienocytes. 

 Compare with inucor. 



Sujjplementary Observations on Filamentous Algoe. 

 Experiments 



1. Observe the bubbles constantly given off by these 

 plants when in the sunshine. Collect the gas by placing 

 vigorous cladophora in an inverted test tube tilled with 

 water. Support the tube so that the lower end is below 

 the surface of the water in the aquarium jar. The process 

 will be very slow, but when enougli gas is collected, remove, 

 under instructions of your teacher, and test with a glowing 

 wood splinter thrust into the gas. What happens and 

 what gas causes such action? Or fill a test tube with 

 water, invert and insert a short-stemmed glass funnel stem 

 into the tube, and fasten the whole over vigorous algae. 

 This plan hastens the collection of the gas. These methods, 

 at the best, furnish a very slow accumulation of gas, pos- 

 sibly much mixed with air. In this gas making, the plant 

 is engaged in the very important work of preparing food 

 for its own use. Th,e crude materials are water and carbon 



