78 ERTTHEA. 



CONCLUSION. 



The formation under certain circumstances of leaves of the 

 type of those in typical Anacrogyuous Jungermanniacese is 

 one more point in favor of placing Sphaerocarpus with these 

 rather than with the Ricciacese, with which it agrees however, 

 very closely in its germination, apical growth, and the struc- 

 ture of the sexual organs. 



EXPLANATION OF FIGURES. 



Fig. 1. Two germinating spores of Splicer ocarpiis terres- 

 iris var, Californicus, X about 70. 



Fig. 2. Apex of the young plant showing the first divi- 

 sions, X about 400. 



Fig. 3. A somewhat older stage than that shown in Fig. 2, 

 seen in horizontal (optical) section, the apical cell (x), x 

 about 400. 



Fig. 4. Young thallus seen from the side showing the long 

 germ-tube and first rhizoid (r.), X about 70. 



Fig. 5. Horizontal (optical) section of young thallus with 

 two-sided apical cell (x), X about 200. 



Fig. 6. Similar section of young thallus with apparently 

 more than one initial cell, X about 200. 



Fig. 7. Longitudinal section of young thallus, X about 

 200. 



Fig. 8. Surface view of young thallus with two-sided 

 apical cell, X about 400. 



Fig. 9. Small female plant, showing abnormal develop- 

 ment of the thallus, X 13, (1) lobes between the branches. 



Fig. 10. A similar, but larger male plant, X 3. 



