330 MISS M. G. SYKES ON THE SEEDLING AND 
at the base of the leaf. On the inner side of the leaf-groove a second prominent 
white ridge is now to be distinguished, resulting from the intercalation of a second 
elongated area of meristematic growth, internal to the leaves. This second ridge 
forms the inner lip of the groove and is shown in fig. 4c (Br.), where it appears as a 
narrow band encircling three sides of the base of each of the cotyledonary buds: its 
erowth has already raised up the cotyledonary buds above their original level It is 
from this inner ridge that the inflorescences commonly arise. 
Further Growth—tThe general form attained in Stage 3 is but little modified in the 
mature plant. The method of growth from this stage has been carefully described by 
Bower. The changes in form are chiefly brought about by cell-divisions at the base of 
the leaf-groove, by means of which the inner and outer ridges grow in size and become 
still further raised *. 
The uplifting of the cotyledonary buds by the growth and expansion of the inner ridge 
gives the growing plant a very remarkable appearance. "The buds, or lobes of the crown, 
as they have been called, become much enlarged and flattened, forming the well-known 
“table-top " so characteristic of old Welwitschia plants; they are usually merged in one 
another on their contiguous sides, the line of fusion (F, fig. 9) being often hardly or not 
at all distinguishable. It is obvious that in these cases the apex of the plant has become 
buried by the growth of the “crown” and is incapable of further growth. 
Pl. 34. fig. 9 represents a young plant which has attained to the mature form. The 
growth of the cotyledonary buds and the intercalation of the inner ridge has pushed 
apart the two sides of the leaf- groove, and has consequently separated widely the formerly 
closely approximated leaves. Both inner and outer ridges still show traces of their 
double origin (O!, O^, fig. 9 a). 
Origin of the Inflorescences.—The origin of the inflorescences in young and mature 
plants has been described by Bower f and Pearson ¢ i. Among my young plants were 
some very early stages in which only one or two inflorescences had as yet been developed. 
In each case they were borne on the inner lip of the groove, 2. e. the inner meristematic 
ridge, and the first-formed inflorescences always occurred opposite the line separating 
the two cotyledonary buds, in what appears to be always the oldest portion of the 
intercalated region (fig. 9). Their formation is generally confined to the inner ridge, but 
Pearson has recorded as not uncommon cases in which the outer ridge becomes much 
enlarged and zoned, and gives rise to inflorescences, 
Modifications of the Normal Development.—It has been remarked above that in normal 
cases the apex is buried by the growth of the crown and no further development is 
possible. 
In quite a large number of instances it is found that the lobes of the cr own are nol 
merged in one another, at any rate up to a considerable age. In these cases meri- 
stematic growth produces transverse continuations of the inner rid ge so that each bud is 
completely encircled. Fig. 7, although drawn for a different purpose, may, if AM 
* Bower, IT. pp. 583-585, pl. 33. fig. 10. 
t Bower, Il. p. 590, figs. 13 & 14; see also Hooker, 1863, 
+ Pearson, II. pp. 332-333. 
