112 



THE SCIENCE OF LIFE. 



Chara springs. This temporary structure is termed the 

 pro-embryo. 



In Chara vulgaris the circulation, or movement, of 

 bioplasm in vegetables was first 

 discovered. (Chap. II, Sec. 7, 

 and Chap. IV, Sec. 6.) 



3. The Liverworts, or HEPA- 

 TIC^, form a class or group of 

 plants generally considered in- 

 termediate between Lichens 

 and Mosses. They are fur- 

 nished with leaves, or lobed 

 fronds, with rootlets on the 

 F.G. 4 i.-portion of Antheridium under surface, which send up 



of Chara. x. Several jointed filamnts j fc - { d 



attached to a vesicle. 2. End of one J o 



of the tubes, a spiral thread escaping, shield-like disks, bearing an- 



3. A tube nearly empty. 4. An an- 



therozoid with its cilia. theridia, or radiating bodies, 



bearing at first archcgonia, or female organs, and after- 

 ward sporangia, or spore-cases. (Fig. 42.) 



The arrangement of 

 the stomata, or breath- 

 ing pores, in these hum- 

 ble plants is far more 

 complex than we find 

 it in others. The leaves 

 of all the higher plants 

 have cavities, or air- 



SDaCCS Communicating 



* 

 with the external WOrld 



by openings, or pores, which are guarded by elastic 

 cells ; but in Marchantia polymorpha the green sur- 



FIG. 42. Frond of Marchantia polymorpha, 

 with gemmiparous conceptacles, and lobed re- 

 ceptacles bearing pistillidia. 



