PBTCOPHTTA. 149 



ered single-celled, but rather rows or aggregations of cells 

 which have not become separated from one another by 

 partitions. Such a plant-body is a ccenocyte. 



263. Botrydium {Hydrogastracem). — One of the sim- 

 plest of the Green Felts is the little Botrydium (Fig. 77), 

 which occurs on the surface of damp 

 ground. It consists of a nearly globu- 

 lar, green body above the ground, with 

 tapering, colorless branches below, 

 penetrating the soil. It is not, as one 

 might suppose, a single cell, but an 

 aggregation of cells, the plant being 

 non-septate. It reproduces by form- 

 ing zoospores, some of which develop Fio. rt.—A. plant of 



Botrydium, Mgnly mag- 



directly into new plants, while others nifled, with conjugating 



■^ ■*■ zoospores. 



unite and form resting spores. 



264. The Green Felts ( Vauclieriacem) are good repre- 

 sentatives of one of the highest families in this order. 

 They are coarse, green, tubular plants which grow in 

 abundance on the moist earth in the vicinity of springs, 

 and in shallow running water, forming dense felted masses. 



265. The asexual reproduction consists of a separation 

 of a part of the plant-body, sometimes a swollen lateral 

 branch, sometimes only the protoplasm of such a branch. 

 In the latter case the protoplasm may escape as a zoospore 

 {A, Fig. 78) which eventually forms a wall around itself, 

 and then proceeds to elongate into a new plant-body. 



266. Sexual reproduction takes place in lateral branches 

 also. Both antherids and oogones develop as lateral pro- 

 tuberances upon the main stem {og, og, h, Fig. 78). The 

 male organ (antherid) is long and rather narrow, and soon 

 much curved; its upper portion becomes cut ofE by a par- 



