1917] 



DUNN—DUMONTIA 



43 1 



auxiliary cell apparatuses in the upper portion of their thalli. 

 Carpogonial branches therefore were probably initiated on these 

 plants only a few days before they were collected. The average 



Fig. 6. — Tetrasporic plant showing much inflated main axis and branches; Xo . 5 



size of the male is less than that of the female plants. The maxi- 

 mum height of the male plants examined was 20 cm. They could 

 be distinguished from the young female plants only by microscopical 



