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BIOLOGY AND HUMAN LIFE 



The distinction between having chlorophyl and not having chlorophyl 

 separates all the thallophytes into two main groups, the algae and the 

 fungi. 



B. Alce. The chlorophyl-bearing thallophytes. 



Fig. 41. Alternation of generations in the Hfe history of the fern 



G, the gametophyte, or gamete-bearing plant; /, the female gamete organ; in, the 

 male gamete organ; e, the fertilized egg. S, the sporophyte, or spore-bearing plant; 

 s, the spores discharged by the spore-bearing organ. The spore develops into a 

 gametophyte; the gametes (egg) always give rise to a sporophyte. The alternate 

 generations reproduce in different ways — one by means of gametes, or sexually, the 



other by means of spores, or asexually 



1. The green algae. Usually yellowish green. {Examples. Pleu- 



rococcus, desmids, Spirogyra, Vaucheria, stonewort, sea 

 lettuce.) 



2. The brown algae. Mostly marine. {Examples. Bladder wrack, 



Laminaria, Sargassum, diatoms, sea palm.) 



