C. A, BARBER. 47 
Fig. 2 shows the end of the sucker of another self-attached haustorium. 
It is difficult to state where the sucker ends and the host 
begins. The vessels are enlarged at their ends (see fig. 5). 
Fig. 3. A portion of the vascular system of the axis in the section shown 
in fig. 1, further enlarged. It should be compared with fig. 3 
of the last Plate which, however, has been inadvertently 
drawn on a larger scale, 
In haustoria fixed on Olax, large and small vessels occur as well as 
fibro-crystal masses and _ well-developed sieve-tubes. These are 
absent in all other cases examined. 
Fig. 4. Sieve-tubes from fig. 3 magnified further. 
Fig, 5. The endings of the vessels in the sucker lobes before secondary 
thickening has commenced. They are almost globular in form 
(see fig. 2), 
Fig. 6. A small portion of fig. 1 magnified to show the junction of the 
, xylem of haustorium and host. p, vessels and parenchyma 
of haustorium, A, medullary ray and vessel of the host. p is 
cut longitudinally and x transversely. 
Pirate XII.— 
Horizontal sections through Olax haustoria (1) on Albizzia Lebbek 
and (2) on Olax scandens itself. 
Fig. 1. px, protoxylem, x, xylem, c, cambium, Jac, lacuna, c. /., collapsed 
layer. 
Fig. la, Portion of the last figure more highly magnified, mr, medullary ray. 
The section shown in fig. 1 is cut so that one side (the left) is 
higher up in the haustorium than the other. The right-hand 
portion shows a section through the axis opposite the lacuna. 
That on the left traverses the base of the vascular loop, 
shows the lattice-work of vessels in longitudinal section, axd 
again cuts across the vessels transversely as they pass upwards. 
Traces of bast are discernible outside the cambium in this 
latter part. 
Fig. 2. The haustorium cut is a good deal older than that in fig. 1. 
A great development of bast with fibro-crystal masses, cr, is seen 
in the axis. 
Figs. 2a, 2a!, Parts of the vascular system showing the great vessels, as 
compared with the small uniform ones shown in fig. la. 
