On the Seedling Structure of certain Centrospermae. 
BY 
T. G. HILL, * 
Assistant Professor of Botany ; University of London ; University College , 
AND 
ETHEL DE FRAINE, 
University of London ; University College. 
With eight Figures and seven Diagrams in the Text. 
HE study of the seedlings of the Centrospermae 1 has resulted in no 
JL very striking results, the chief features of interest being connected more 
especially with the Natural Order Nyctaginaceae. 
Unfortunately, we were unable to procure seeds of the Natural Orders 
Basellaceae, Batidaceae, and Cynocrambaceae, so that we have no information 
to offer regarding the structure of their seedlings. The same remarks also 
apply to certain genera of the other Natural Orders of the Cohort, but 
sufficient of the rest have been examined to give a general idea of the seedling 
anatomy of those orders centring around the Phytolaccaceae. 
The characteristic mode of transition of the Centrospermae is Van 
Tieghem’s type 3, and although this has been described in previous papers 
it appears desirable to draw attention to its features in one example, 
Calandrinia Menziesii , in order that much repetition, when dealing with 
the different plants, may be avoided. 
PORTULACACEAE. 
Calandrinia Menziesii, Torr. et Gray. The seedlings of this plant are 
very small, with fleshy cotyledons which show no internal differentiation 
into palisade tissue. In this species, and also in C. amoena , C. speciosa i 
C. umbellata , and C. grandiflora , a short cotyledonary tube is present. Each 
seed-leaf, which in transverse section is circular in outline, has in its upper 
part three bundles, one central and two lateral, of which the former is the 
largest. Tracing these strands downwards, the central one soon shows 
1 T. G. Hill: On the Seedling Structure of certain Centrospermae. Brit. Assoc. Rep., Sect. K, 
York, 1906. 
[Annals of Botany, Vol. XXVI. No. Cl. January, 191a.] 
