146 de Fraine .— The Seedling Structure of certain Cactaceae. 
one is usually accompanied by decrease in size of the other. In R. Eynesii , 
E. oxygona , and E. Zuccctrinii they closely resemble the ‘ cotyledonary 
buds’ of the Cereus group, but in E. Lagermannii and E. multiplex the 
cotyledons are, comparatively speaking, small, and the tubercles are well 
developed, tufted with spines, and have a vascular bundle running to the 
base of the cushion. 
Vascular Relationships between the Cotyledons and the 
Tubercles. 
The behaviour of the cotyledon- and tubercle-bundles is extremely 
erratic, and varies not only within the species but even in the opposing 
pairs of bundles of a single seedling. 
The simplest case was that found in E. multiplex , Series 1 (Diagram 8, 
Diagram 8 . Echinopsis multiplex , Series 1. Behaviour of cotyledonary and tubercle 
bundles. 
Fig. 1), in which the cotyledonary bundles (c v e 2 ) both showed bifurca¬ 
tion of the phloem by the time the tubercle-bundles (p, p) appeared. 
The strand p rotated through an angle of 90°, moving outwards as it did so 
to meet the incoming cotyledonary trace (c^, and p finally fused laterally 
with c l (Diagram 8, Fig. 2); in a similar manner t 2 fused with c 2 . By 
this means two bundles, such as are shown in Diagram 8, Fig. 3, are produced. 
This is a parallel case to what occurs in Cereus tortuosus. 
Echinopsis multiplex , Series 2, showed a similar sequence of events as 
far as the larger cotyledon was concerned, but in the smaller seed-leaf the 
two strands behaved differently. In this case the tubercle-trace rotated 
and moved outwards to meet the seed-leaf-trace; this latter also rotated 
slightly but did not bifurcate, and the two strands together formed one 
bundle by the fusion of their protoxylems. In this cotyledon the tubercle- 
