14 ON SEEDLINGS 



Owing to the number of seeds and embryos in each fruit there 

 must be a great competition amongst the seedlings in a state 

 of nature, since there is no means of dissemination, as in 

 fruits which dehisce. 



Seedlings. In. general characters there seems to be very 

 little variation amongst the cotyledons of this Order, although 

 they vary slightly in detail. Those of Tetragonia expansa, 

 above-mentioned, are the longest and narrowest. Amongst the 

 species of Mesembryanthemum they are broadly or narrowly 

 oblong, rounded at the apex, sessile and connate, or perfoliate 

 at the base, and so succulent that no venation is discernible, 

 except sometimes a faint indication of a midrib. 



Mesembryanthemum tricolorum (fig. 401) presents a short 

 and comparatively broad type. The leaves are linear or 

 semiterete, and succulent with the first pair developed close 

 to the cotyledons, or if the seedlings are crowded at some 

 distance from them. The leaves of M. capitatum are also 

 semiterete. The cotyledons of M. serratum and M. echinatum 

 (fig. 402) closely conform to those of M. tricolorum ; and the 

 primary leaves are subulate, semiterete or obtusely trigonous 

 and succulent. 



A modification of the above type is exhibited in the cotyle- 

 dons of M. cordifolium, which are broadly oblong, foliaceous, 

 flat but succulent, minutely wrinkled or areolated, 1-2-1 -5 cm. 

 long, and 7-9 mm. wide. It is a significant fact that the 

 leaves are also flat and ovate, or subcordate, from the first 

 pair onwards. The cotyledons are however slightly connate 

 at the base. A type with narrow cotyledons occurs hi M. 

 pinnatifidum where they are linear-oblong. The primary 

 leaves are radical, but the stem ultimately becomes elongated 

 and procumbent or trailing, with cauline leaves. The first 

 pair are spathulate and entire, followed by others which are 

 sinuately pinnatifid with rounded alternate segments. 



Mesembryanthemum tricolorum, Haw. (fig. 401). 



Primary root short, tapering, giving off a few lateral fibrils ; 

 upper part succulent. 



Hypocotyl succulent, stout, tapering from the cotyledons down- 

 ward, variable in length and subsequently giving off a few short 

 rootlets. 



