



Durand : Marchantia polymorpha 333 



Explanation of figures (plates 2±-2S) 



All figures were drawn with the aid of the camera lucida. Figures 1-30, 32-69, 

 102, and 103, were drawn with the B. & L. one-eighth objective and one-inch ocular. 

 Figure 31 was drawn with the one-twelfth objective and one-inch ocular. Figures 70- 

 101 were drawn with the one-sixth objective and one-inch ocular. The exact magnifi- 

 cation is indicated with each plate. 



Antheridium 



Fig. 1. Longitudinal section of gametophore showing I -celled rudiment of the 

 antheridium. 



Figs. 2, 3. The antheridial rudiment has divided by a transverse wall into the 

 mother-cell of the stalk and mother-cell of the antheridium proper. 



riGS. 4, 5. Same as last but from transverse section of the gametophore ; anther- 

 idium enlarging. 



Fig. 6. Same as last but young antheridium becoming more deeply buried by the 

 upgrowth of the surrounding cells. 



*IGS. 7, 8. The whole organ more deeply buried ; antheridial mother-cell divided 

 by a transverse wall. 



frlG. q. As in last but division beginning in mother-cell of the stalk. 



Figs. 10-12. As in last but vertical division beginning in mother-cell of anther- 

 idium proper. 



Fig. 13. Antheridial mother-cell divided by two transverse walls. 



igs. 14-18. As in last but showing variations in division in the stalk, and suc- 

 cessive steps in vertical division of antheridium. 



igs. 19-23. Steps in the periclinal division of the antheridium to separate the 

 *all from the spermatogenous tissue within. 



igs. 24, 25. Antheridium enlarging; beginning radial division in the wall, and 

 transverse division of spermatogenous tissue. 



■ 26 ~ 2 8. Further radial division in the wall ; successive steps in division of 

 spermatogenous tissue by transverse and vertical walls into cuboidal cells ; increasing 

 massiveness of the stalk. 



IG - 29. Antheridium one fourth to one third grown ; original vertical and trans- 

 v *se walls plainly evident. 



IG - 30. A block of cuboidal cells from a mature antheridium just before their 

 Agonal division to form the spermatids. 



* 3*- A block of cuboidal cells from same antheridium as figure 30, showing 

 ^agonal division to form the spermatids. Note that in some of the cells diagonal walls 

 PPear between the spermatids. One-twelfth objective. 



Archegonium 



.,„ , * 32 » 33> 40. Mother-cell of the archegonium cut off from the cell of the gam- 



F t s r ° m Which il has ari *en. 



* ' 34> 35- The mother-cell divided by one obliquely vertical wall. 



• 3 , 37. The mother-cell divided by two obliquely vertical walls. 



J - • Transection of young archegonium, showing relation of the two walls. 



thp m 1 ' 39, 4 °' The axial cel1 divided by a transverse wall to form the cover- and 

 ,be "jother-cell of the axial row. 



,G - 41. Cover-cell divided. 





