THE BRYOPHYTES. 169 



the frond, and the antheridia grow from the upper surface 

 of the scalloped-edged circular top. The antheridia are 

 modified hairs. The female inflorescence is borne on 

 branches of other plants of about the same height as the 

 male branches. The tops differ in that the lobes are 

 slender and are cut well in toward the center. The top 

 has been compared to a wheel without the rim. The 

 archegonia are borne on the under side, concealed in tis- 

 sues in the grooves of the rays. These are also modified 

 hairs. (See Figs. 96, 98, and 99.) 



The antherozoids, borne in the antheridia, swim out 

 when there is moisture on the plant drops of dew are 

 sufficient and find their way to the archegonia. Pass- 

 ing down through the neck, they come in contact with the 

 egg cells, which they fertilize. A spore fruit results, and 

 the spores develop by fission of cells into small and simple 

 growths called protonemce, from which new plants arise. 

 (Figs. 97 and 101.) 



COMMON LIVERWORT. 1 PRACTICAL STUDIES. 



1. Examine with the naked eye a considerable number 

 of specimens of Liverwort. It is not possible to find all 

 the different stages of development at some seasons of the 

 year, and alcoholic material must then be used in part of 

 the work. Find, if possible, plants bearing cupules, some 

 bearing the male inflorescence, and some bearing the female 

 inflorescence. Notice how the plants branch. Examine 

 the end of each branch. What do you observe ? Do the 

 two parts which result from a given division develop into 

 branches of equal size ? Do you find a midrib ? If so, 

 can you trace it along the main stem of the thallus and 

 along the branches ? Measure and state the length and 

 breadth of several plants. Observe the color. Are all 

 1 Similar Practical Studies may be made of any other species of Liverwort. 



