APPENDIX 



CHAPTER II 



P. 9. The occurrence of gemmae of endogenous origin has also 

 been observed in other species of Aneura, and the multicellular gemmae 

 of Metzgeria have been found to originate also in much the same 

 manner. (Goebel (8), Cavers (g), Evans (3).) Recently Buch (i) 

 has described unicellular gemmae of endogenous origin in a leafy 

 Uverwort, Haplozia caspitica. 



P. 10. A recent study of Sphagnum (Bryan (i) ) shows that in 

 this Moss the apical growth of the archegonium is very Umited. 

 The terminal cell (cap cell), early undergoes a vertical division, and 

 no basal segments are cut off from it. In a number of Liverworts, on 

 the other hand, there is a limited apical growth (CampbeU (37, 39) ), 

 although none of the canal cells arise from the terminal cell. It is 

 thus clear that the differences between the archegonium in the 

 Liverworts and Mosses are less marked than has hitherto been sup- 

 posed. 



P. 12. The origin of the sexual organs of the Archegoniates is 

 very obscure. In some respects they resemble most nearly those of 

 the Characeae, but it is doubtful whether these resemblances indicate 

 any real relationship. 



Perhaps the most plausible explanation of the origin of these 

 organs from those of the Algae is that of B. M. Davis (3), who thinks 

 that they most nearly resemble the plurilocular "gametangia " of 

 certain Brown Algae. He does not think that there is any genetic 

 connection between the latter and the Archegoniates, but rather that 

 the connection is to be sought with some Green Algae which had 

 gametangia similar to those of the Phaeophyceae. There are still in 

 existence species of Schizomeris and Draparnaldia which show an 

 approach to these structures, but presumably the direct ancestors of 

 the Archegoniates are no longer in existence. 



Davis thinks that the outer cells of the gametangium through 

 sterihzation became the wall of the antheridium or archegonium, 



607 



