32 BBITISH HEPATIC^. 



annual shoots spring from the ventral aspect, and may be called adventitious. Thus 

 if we isolate one or two colesuliferous stems from a luxuriant tuft, at first view the 

 central axis appears continuous, and the shoots interrupted at pretty regular intervals, 

 each of which bears an involucre at the apex. But on careful examination we find 

 that the axis is not continuous, but that each younger stem originates from the axil 

 of an amphigastrium beneath the involucre of the former season. Other innovations 

 may spring from different parts of the ventral aspect, or very rarely from the axil of a 

 leaf, but only one of these is continued in the line of the main stem. 



Whilst examining this, and allied species, I have sometimes attempted to estimate 

 the age of the shoots. Nearly all Liverworts are described as perennial, rejuvenescence 

 taking place from the apex, whilst the older parts gradually wither and crumble away. 

 The annual shoots are limited in growth, the first leaves being smaller, and the ter- 

 minal ones usually colesuliferous, or bearing perigonial leaves ; so that if we can count 

 the number of these interruptions, they may be looked upon as representing the growth 

 of so many years. 



Although If. conipressa is so delicate a species, the leaves and stems seem to 

 withstand decay longer than usual. In remarkably fine shoots, I have been able to 

 find as many as ten to twelve intervals of growth ; and (supposing the fructification to 

 be annual, which is not always the case) this would give an age of twelve years for 

 the individual shoots, not, of course, for the whole plant. Specimens of Nardia emar- 

 ginata, and Gym. concinnatum may also be met with, bearing traces of from six to nine 

 involucra. T fear, however, the inquiry can never be of practical value. 



Pii. III. Fig. 9. — 1. Shoot natural size. 2. Portion of the same x 8. 3. Stem- 

 leaves. 4. Perigonial leaf and antheridia. 5. Leaf-cells x 250. 6. Involucre, the 

 lower portion laid open, showing the base of the calyptra, and the manner in which the 

 involucral leaves are attached to the walls. 7. Spores and elaiers. 



y. Southbya, Spruce {Eucalya;, Lindb.). 



9. Naedia obovata {N. ab E.). 



Pl. XI. Fig. 35. 



Paroicous ; stems ascending, simple or fasciculately innovant, 

 clothed with rootlets of a claret colour ; leaves rather distant, 

 roundish-ovate, immarginate, vertically patent-divergent, from a 

 contracted, concave, sheathing base ; involucral leaves larger, obo- 

 vate, recurved at the apex, connate with each other, and with the 

 colesule for f rds of its length ; colesule obovate, obtusely 5-6-plicate, 

 at length quadrifid; capsule rotundate; amphigastria confined to 

 the involucre. 



Jungermannia ohovata, 'S. ab E. Leberm. Eur. i. p. 332, ii. p. 474 ; G. L. N. 

 Synop. Hepat. p. 95, n. 44 ; Flor. Danica, Sup. t. 118, n. 2 j Hartm. Skand. Fl. 9, ed. 

 ii. p. 88 ; Moug. & Nestl. Stirpes Voges. Rhen. n. 935 ; G. & K. Hep. Eur. Ex. 

 n. 266, c. icon. n. 352. 



J. atrovirens, Dum. Syll. p. 51, n. 52 (?). 



J. tersa, N. ab E. 1. c. ii. p. 471 (ex parte) ; et Syn. Hep. p. 94, n. 40 (ex parte). 



Southbya obovata, Lindb. Eevis. Grit. FI. Dan. p. 113 (1871). 



Eucalyx obovata, Lindb. Aftryck ur Botaniska Notiser, p. 15 (1872). 



