IV. 



THE ANTHOCEROTES 



133 



faster than the others and divides into the tgg cell and the 

 ventral canal cell. The cover cell divides by a vertical wall 

 into two nearly equal cells, and these usually, but not always, 

 divide again, so that four cells arranged cross-wise form the 

 apex of the archegonium. In A. fiisiformis in nearly ripe 

 archegonia I have sometimes been able to see but two of these 

 cover cells, but ordinarily four are present. The neck canal 

 cell divides first into two, and these then divide again, so that 

 four cells are formed. This was the ordinary number in A. 

 fiisiformis. In a nearly ripe archegonium of A. Pearsoni five 

 neck canal cells w^ere seen, but in no cases so many as 



B. 



C. 



Fig. 69. — Anthoceros fusiformis. A two-celled embryo within the archegonium venter, 

 X600; B, C, two longitudinal sections of a four-celled embryo, X600. 



Janczewski describes for A. Iccvis, where he says as many as 

 twelve may be present. 



If the earlier divisions in the archegonium of Anthoceros 

 are compared with those of the other Hepaticae, the most strik- 

 ing difference noticed is the separation of the cover cell. In 

 the latter the first division of the axial cell separates the cover 

 cell from an inner one, and by the division of the latter the 

 primary neck canal cell is cut off from the central cell. In 

 Anthoceros the neck canal cell is cut off from the outer, and not 

 from the inner cell. 



