OF CEYLON AND INDIA. 
389 
under the circumstances it should be described as having no 
definite form. 
Not only Joes this plant bear a large number of big leaves 
on its primary axis, but it also produces a great number of 
leafy secondary shoots upon the thallus, so that it could 
hardly be more incorrectly described than has hitherto been 
done Before it has reached a diameter of more than one 
centimetre, it begins to produce these leafy shoots, two of 
which are shown in PL XXXIY., fig. 1, upon a very young 
seedling. The seedling shown in the figure is clasping an 
old capsule, and has already become lobed. The primary 
axis had become broken olf very early, and this no doubt 
accounts for the large size of these leafy shoots upon so 
small a thallus, for, as a rule, they have hardly begun to make 
their appearance above the surface in a thallus of this size 
{cf. fig. 3). Their first appearance is seen in PI. XXXVI., 
fig. 3 {an.). They appear in the zone of growth close to the 
margin of the thallus, as little round markings on the upper 
surface. A. trifling distance further back they pass into the 
region of elongation of cells, and become elliptical. The 
centre of the mark is usually green, but the cells round it 
as a rule show a deep red colour, like those of the margin 
of the thallus. Soon afterwards the first leaf of the shoot 
breaks through the superficial cells and appears above the 
surface of the thallus, so that in this species, as in all the 
others, the leafy shoots borne upon the roots are' endo- 
genous. A second leaf soon follows the first, and the plane 
of the two leaves is at right angles to the margin of the 
thallus. More leaves soon appear, till the shoot, when fully 
grown (PI. XXXIV., fig. 4), may consist of leaves as much as 
5 cm. long, and five, six, or more in number. These leaves 
exhibit the same structure and appearance, though usually 
on a smaller scale, as the leaves of the primary shoot. The 
growing point of the shoot does not at first elongate or 
appear above the surface of the thallus, and there is, perhaps 
in consequence of this fact, no appreciable dorsiventrality in 
the shoots at this period of the life-history. They remain 
