LIVERWORTS: MARCHANTIA. 



227 



midrib, as shown in figs. 257, 261. Tiie growing point of the 

 thalhis is situated in the little depression at iht- lYcc end. 11" we 

 examine the upper surface with a hand 

 lens we see diamond-shaped areas, and 

 at the center of each of these areas are 

 the openings known as the stomates. 



484. Antheridial plants. — One of 

 the male plants is figured at 257. It 

 bears curious structures. 



each held aloft by a shoit 

 stalk. These are the an 

 theridial recep- 

 tacles (or male 

 gametophores). 

 Each one is cir- 

 cular, thick, and 

 shaped some- 

 what like a bi- 

 convex lens. The upper surface is marked by radiating fur- 

 rows, and the margin is crenate. Then we note, on careful 

 examination of the upper surface, that there are numerous minute 

 openings. If we make a thin section of this structure perjjen- 



l'ig.2S7. 

 Male plant of marcliantia bearing antberidiophores. 



Fig. 258. 

 .Section of antlieridial receptacle from male plant of Marchantia poljTnorpha, showing 

 ca\-ities where the antheridia are borne. 



dicular to its surface we shall be able to unravel the mystery of 

 its interior. Here we see, as shown in fig. 258, that each one 

 of these little openings on the surface is an entrance to quite 



