444 EXPLANATION OF THE FIGURES. 



FIG. 



14*. A similar body in the act of dividing, x 400. 



15. A young archegonium with the adjoining tissue, cut through longitudinally, 



X 300. 



16. An arcliegonium more fully developed, after the formation of the germinal 



vesicle in the basal cell, x 300. 



17. Portion of a longitudinal section of a shoot perpendicular to the surface, 



bearing an archegonium just impregnated. A bud which has been cut 

 through is seen in the tissue underneath, x 300. 



18. Longitudinal section of an archegonium (with the adjoining cells) with a 



bicellular fruit-rudiment, x 300. 

 18*. The mouth of the latter seen from above, X 300. 



19. A similar preparation with a multicellular fruit-rudiment, x 300. 

 20a. A 3-cellular fruit-rudiment, detached, x 300. 



20*. The same preparation turned round 90°, x 300. 



21 a . Longitudinal section of a further developed fruit-rudiment, x 300. 



21*. The apex of a detached fruit-rudiment, similarly developed, seen from the 

 outside, x 300. 



21 c . Optical section of the preparation in the same position, X 300. 



21 d . Optical section of the same after being turned 90° round its longitudinal 

 axis. 



22. Longitudinal section of a further developed fruit-rudiment, x 250. 



23 a >*. Optical longitudinal sections of the upper end of a more advanced fruit- 

 rudiment. The position of 23* differs from that of 23" by a revolution 

 of 90° round the longitudinal axis, x 250. 



24. Transverse sections of a similar fruit-rudiment, x 80. 



25. Apex of a slightly more developed fruit-rudiment, separated from the lower 



portion by a transverse section, and seen from above, x 150. 



PLATE II. 



1. Longitudinal section of a young fruit-rudiment enclosed by the surround- 



ing tissue, x 150. 



2. Longitudinal section of a further developed condition of the same parts. 



A large cavity filled with mucilage has been formed above the apex of 

 the fruit-rudiment. Some of the cells of the wall have grown out into 

 multicellular hairs. X 120. 



3. Upper portion of the wart-like protuberance (above the upper surface of 



the stem) by which the young fruit is enclosed ; cut off so that the upper 

 end of the fruit is visible. The cells of the jointed hairs which traverse 

 the mucilaginous mass in the interior of the cavity above the fruit, have 

 already become detached. X 100. 



4. Longitudinal section of the upper end of a fruit at the moment of breaking 



out from the sheath. Only the mucilaginous mass and the dry cellular 

 tissue covering it are shown in detail ; the fruit and the sheath are only 

 in outline, x 200. 



5. Longitudinal section of a half-developed fruit just after breaking forth 



from the tissue of the stem, x 100. 



