16 Britton and Taylor : Life History of Schizaea pusilla 



time. The spore remains attached for some time after the forma- 

 tion of antheridia. 



The gametophyte is a filamentous protonema, irregularly 

 branched, bearing both antheridia and archegonia on the same 

 filaments ; and producing rhizoids from specially modified cells 

 which are inhabited by a symbiotic fungus. 



The antheridia occur singly, or in groups on special branches 

 bearing antheridia alone. They are produced in great numbers 

 though but few ripen. They are simple in their structure and 

 the first wall formed in the antheridium is parallel with the wall 

 cutting it off from the lateral branch, forming a pedicel. A small 

 number of antherozoids are produced in an antheridium, which 

 are enclosed in a membrane when they escape from the antheridium. 



The archegonia arise at, or near, the base of the filaments, 

 either directly on the filament or, more often, on cushions formed 

 by the division of the cell of the filament. They are character- 

 ized by the uniformity of the neck rows and the large size of the 

 stigmatic cells. 



The foot is a large, well-defined organ, remaining attached to 



formatio 



ryi 



which 



is far advanced before it breaks through the calyptra. 



The primary root is persistent The second and third roots 



have a vestigial sheath through which they do not break until 



after the development of the root-cap. The root-cap consists of 



four large pear-shaped cells inflated on the side away from the 

 root tip. 



The rhizome is erect, always forming a protective covering 

 over the growing end ; the trichomes are large, turn brown early, 

 and are persistent. 



There is a central concentric bundle with a well-marked endo- 

 dermis. Sclerosis takes place in the entire cortex, the cells of 

 which, with the epidermis, are filled with starch. The epidermis 

 and cortex are often invaded by a fungus hypha. 



The sterile and fertile leaves have two rows of large stomata, 

 on the dorsal side, alternating with two or more rows of glands; 

 these glands are small and sometimes wanting on the fertile leaf 

 The young leaves are more or less completely clothed with 



