254 Mr Barber, Parasitic Trees in Southern India. 
referred to the Memoirs already mentioned. In the series of 
diagrams on Plate III., the haustoria of Santalum album, Thesium 
Wightianum, Buckleya Quadriala from Japan as figured by Kusano, 
Osyris arborea, Opilia amentacea, Cansjera Rheedii, Olax scandens 
and Ximenia americana are figured, all having successfully pene- 
trated dicotyledon roots in a perfectly normal manner. The main 
points to be noted in these diagrams are the vascular system and 
the collapsed layers, the latter offering important evidence regard- 
ing the changes which have taken place in the arrangement of 
the tissues during development. The study of the haustoria, 
with the exception of Santalum and Olax, is at present very in- 
complete. In all cases (excepting of course Buckleya, the Japanese 
form, which I have not seen) a well-defined gland has been 
observed (Plate II.), and this gland differs more or less in form and 
development in the various genera. It is a somewhat remarkable 
fact that these organs have not been as yet described in any 
haustorium of this class. 
With such materials as are at present available, the following 
appear to be the main characters of the haustoria of Santalaceae 
and Olacaceae collected in South India. 
In Santalum album, Osyris arborea and Thesium Wightianum, 
compound haustoria are common : calcium oxalate crystals are 
found: the collapsed layers terminate upwards opposite to the 
interrupted zone and are of simple origin : a well-developed schizo- 
genous gland is frequently present before penetration, and the 
secretion is subcuticular in the part of the cell directed towards 
the lumen of the gland; there is a distinct interrupted zone 
in the vascular system: the sucker is composed of nucleus with 
cortex. 
Cansjera Rheedii and Opilia amentacea also have compound 
haustoria : there are no crystals of calcium oxalate, their place 
being taken by cystoliths with crystalline plates of calcium car- 
bonate: the collapsed layers end as in Santalum-. a gland is 
present and, although it has not been studied sufficiently as yet, it 
appears to resemble that of Santalum and is simple in structure: 
the interrupted zone is a very marked character in these species. 
In Olax scandens the haustoria, which have been thoroughly 
studied, preseut remarkable differences from all the preceding. 
They are never compound: calcium oxalate crystals are abundant: 
the collapsed layers are formed of three separate parts and termi- 
nate generally far below those already described, passing inwards 
under the vascular loop. This arrangement of the collapsed 
layers indicates considerable differences in development : there is 
a highly complicated gland which is lysigeuous, the lumen being 
filled by parallel rows of cells in various stages of disintegration : 
below the fully developed gland on either side a remarkable clear 
