THE ANTHQCEROTE^E 



127 



colour very strongly, showing that they have become [)artially 

 mucilaginous. This causes them to separate readily, and they 

 are finally thrown off, so that in the open archcgonium no trace 

 of them is to be seen. The walls of the canal cells and the 

 central cell undergo the same mucilaginous change, but here it 

 is complete, and before the archcgonium opens the partition 

 walls of the canal cells completely disappear, and the neck con- 

 tains a row of isolated granular masses corresponding in number 

 to the canal cells. The ventral canal cell is quite as large as 

 the egg, which consequently does not nearly fill the cavity at 



B 



Fig. 59. — Antlioccros fiisiformis (Aust.). A, two-celled embryo within the archegonium venter, 

 Xfioo ; B, C, two longitudinal sections of a four-celled embryo, x6oo. 



the base of the open archegonium (Fig. 57, D) after the canal 

 cells have been expelled. The Q.^g did not, in any sections 

 studied, show clearly a definite receptive spot, but appeared to 

 consist of uniformly granular cytoplasm with a nucleus of 

 moderate size. The upper neck cells in the open archegonium 

 become a good deal distended, and the canal leading to the 

 c^^ is unusually wide. Surrounding the central cavity the 

 cells are arranged in a pretty definite layer. 



Hofmeister was the first to study the development of the 

 embryo in Anthoceros, and described and figured correctly the 



