ANATOMY OF THE ROOTS OF PALMS. 487 
(65) MARTINEZIA LINDENIANA, H. Wendl. 
The cortex is generally similar to that of M. caryotefolia. The bundles of fibres with 
stegmata are present, but the individual lignified elements are wanting, though the whole 
cortex is more or less slightly lignified. The air-spaces are very definite and are arranged 
in several irregular circles. "The endodermis is lignified. "There is a broad fibrous zone 
composed of extremely densely lignified and indurated fibres, whose lumina are almost 
occluded. This zone encloses a central parenchymatous pith provided with some lignified 
elements. The xylem- and phloem-groups are quite normal, with occasional V-formation 
in the xylem. 
. In large roots bundles of fibres occur in the cortex, and a zone of lignified stone-cells 
immediately surrounds the endodermis. A number of fibrous groups, with one, two, or 
three vessels, traverses the pith. 
(66) BACTRIS MINOR, Jacq. 
The external layers are as usual. The inner cortex is provided with irregular air-spaces. 
Stone-cells occur in a zone surrounding the endodermis, and scattered lignified elements 
are found throughout the cortex. The endodermis is lignified and the pericycle is two- 
layered. The fibrous zone is nearly filled with vascular elements. The large internal 
vessels occur in two rings, and the individual elements are closely packed and laterally 
flattened. Xylem V's and Y’s are abundant. Internally there is a pith with large air- 
spaces. 
V. PHYTELEPHANTINE. 
(67) PHYTELEPHAS MACROCARPA, Ruiz et Pavon. 
The cortex is entirely parenchymatous, without any lignified elements or fibres. Some- 
what irregular air-spaces are present. The endodermis is lignified and the pericycle 
one-layered. 
A broad fibrous zone encloses a central pith. 
The protoxylem-groups extend inwards for a long distance, and generally each. is 
provided with two or more large inner vessels. Occasionally these are accompanied 
centrally by one or two smaller vessels. The vessels are closely packed laterally and are 
flattened. The phloem-groups extend inwards nearly as far as do the xylem-groups. 
