OF A PLANT FROM SENEGAMBIAs 157 
plates obliterating the perforations, and the medullary phloem 
was much shrivelled. Dr. Scott, to whom I am much indebted 
for confirming my anatomical observations, thinks it would be 
almost impossible to detect perforations in material so long 
gathered and so dry. I failed to do so with a magnification of 
1300 diameters. The lateral roots show interxylary phloem 
islands ; I have been unable to see very young stages, but I do 
not think they lie within the primary wood as in Chironia and 
Strychnos *. 
According to our present knowledge, this peculiar anatomical 
structure considerably narrows down the systematic limits within 
which the plant must come. To decide as nearly as possible 
what might be its affinity, I have examined plants belonging to 
the orders Loganiacee, Acanthacee, Peneacee, Gentianacee, and 
Melastomacee, but without such definite success as would warrant 
my placing it in any of them. 
In some respects this essay may be instructive in showing the 
limits of plant anatomy in affording characters of value to the 
systematist. 
My anatomical work has been done in the Laboratory of the 
Botanical Department of the British Museum, and I have to 
thank the officials both for advice and material. 
EXPLANATION OF PLATE VIII. 
Fig. 1. Part of plant, reduced one third, 
2. Broad leaf, slightly enlarged. 
3. Narrow leaf, slightly enlarged. 
4, Transverse section of leaf mid-rib, x 150. 
6. Transverse section of part of primary branch: pf.i., phloem 
islands; ph.g., phloem groups: x 150. 
6. Transverse section of phloem island, x 450. 
* Scott and Brebner on Internal Phloem in the Root and Stem of Dicotyledons, 
Annals of Botany, vol. v. p. 281. 
