CALYCULARIA RADICULOSA CAMPBELL 



49 



ones, where old groups of antheridia were present, a second younger group 

 was occasionally found near the apex; and in the rare instances where the 

 thallus forks, each branch may bear an antheridial receptacle. (Fig. 1, C.) 



The antheridia (Figs. 5 and 6) are short-stalked nearly globular bodies 

 and closely resemble those of Pallavicinia, and as usual they are formed in 

 acropetal succession alternately right and left of the apex of the thallus. 



The earliest stages were not found, .so that it is impossible to say 

 whether the early divisions correspond to those observed in other genera, but 

 as the young antheridia resemble so closely those of Pallavicinia, it is to be 



Fig. 6. Development of the Antheridium. 

 A, median section of young antheridium, x about 

 225. B, cross-section of the antheridium of about 

 the same age. C, an older antheridium. D, E, 

 two nearly ripe antheridia, x about 90. 



