EXPLANATION OF THE FIGURES. 451 



FIG. 



7. Longitudinal section of a half-ripe fruit, with the calyptra, two abortive 

 archegouia, and the lower part of the perianth, x 200. 



8 and 9. Young leaves which have not yet formed the rudiments of the two 

 tips, x 500. 



10. A further-developed leaf, x 500. 



11. Tip of a half-developed leaf, x 300. 



12. Section of the tip of a leafless subterranean shoot ; 12*, section of the same 



shoot after being turned round 90°. x 300. 



PLATE IX. 



Figs. 1. — 12. Jungermannia bicuspidata. 



1. Ripe spore, x 300. 



2 — 10. Different stages of germination. 2, 3 one week. 4, 5 three weeks. 

 6, 7 four weeks after sowing. 8 — 10, germ-plants a year old. 2 — 6, 

 X 300; 7, X 200; 8, 9, 10, x 100; 10* is the upper end of fig. 10; 

 turned round 90° and x 400. 



11. Fore-end of a germ-plant at the stage of development shown in fig. 8, seen 



from the outside. The boundaries of the cell of the first degree, and of 

 the first cell of the second degree, as they appear in an optical section, 

 are shown by dotted lines, as is done also in the following figures. 

 X 400. 



11*. The same. The apex of the stem turned round 90°. 



ll c . The same, turned round 270°. 



IT*. The apex of the stem of a more-developed germ-plant, in a position inter- 

 mediate between that of figures 11 and 11*, seen from the outside, 

 X 400. 



12. An abnormal pro-embryo, in which the rudiment of the first leaf-bearing 



axis does not proceed from one of the apical cells of the pro-embryo, 

 but springs from a point lower down (five months after sowing), 

 x 200. 

 12*. Rudiment of the leafy axis, turned round 90°. 



Figs. 13 — 16. Lophocolea bidentata. 



13. Longitudinal section of a terminal bud, x 600. 



14. A very young, 15 a somewhat older leaf seen from above, X 600. 



16. A more developed leaf, the two halves of which have developed unequally, 

 X 300. 



Figs. 17 — 30. Lophocolea heterophylla. 



17 — 25. Germination of the spores; (17, a spore just detached, 18 a spore 

 twenty-four hours afterwards), x 200 except fig. 23, which is X 600. 



26. Production of the first leafy axis out of the pro-embryo, x 250. 



27. More advanced germ-plant, whose hinder end is already dead, x 200. 



28. Lower portion of a germ-plant which has already formed some perfect leaves, 



x 100. 



