Seedling Structure of certain Centrospermae . 187 
PHYTOLACCACEAE. 
Phytolacca Paraguay ensis , ?, in most of its transition characters is very 
like Amaranthus sylvestris. There is the same division of the chief cotyle- 
donary bundle and the isolation of the protoxylem-elements which takes 
place in the base of the blades of the seed-leaves. The only feature of 
difference is that in P . Paraguay ensis the union of the two laterals with the 
central seed-leaf-strand is effected at the extreme base of the petioles. 
Phytolacca dioica> L., only differs from P. Paraguay ensis in the fact that 
the two halves of the main seed-leaf-bundle are more compact and their 
separation is less well marked. 
Phytolacca acinosa , Roxb., which has a somewhat smaller seedling, does 
not show, so far as has been seen, the separation of the protoxylem of the 
cotyledons in the seed-leaves themselves ; otherwise, its vascular rearrange- 
ments are like those of the two preceding species. 
Phytolacca decandra. The transition phenomena of this plant, judging 
from Gerards account, 1 do not appear to differ in any important feature 
from those of the foregoing species. 
Rivina , which has been investigated by Dangeard, 2 also follows type 3, 
and so also does Basella (N.O. Basellaceae). 
AIZOACEAE. 
Mesembryanthemum. All the seedlings of this genus are of a fleshy 
habit, which is more marked in some than in others, and their cotyledons 
are more or less adnate. This union may be nothing more 
than the formation of a cotyledonary tube, as in M. cry - 
stallinum , L. ; in other cases the ad nation may be quite 
extensive, especially in the more fleshy forms, the seed- 
leaves being joined by their ventral surfaces for most of 
their length, as in M. Bolusii. Fig. 5 illustrates the 
two extreme forms of young seedlings ; of the species 
examined, M. linguaeforme , M. tigrinum , Haw., and 
M. truncate Hum , Haw., very closely resemble M. Bolusii , 
the chief differences being those of size ; thus M. tigrinum 
is about half as large as M. Bolusii , and M. truncatellum 
about one-third or a quarter the size of this same plant, also it is 
more rounded. M. crystallinum resembles M. tricolorum , Haw., and 
M. rhomboideum is somewhat intermediate in appearance. 
The transition phenomena are like those of many of the foregoing 
plants, Calandrinia Menziesii for instance. In M. tricolorum , M. crystalli - 
Fig. 5. A. Me- 
sembryanthemum 
crystallinum ; B. 
M. Bolusii . Na- 
tural size. 
1 loc. cit. 
2 loc. cit. 
