40 DR. J. D. HOOKER ON THE GENERA AND SPECIES 
do these quite accord with one another, but only in what I assume to be mere individual, 
and not specific characters. 
Prof. Liebmann sums up the differences between the Mexican and the Brazilian indivi 
duals, as residing in the more globose female capitulum, shorter stem, more shortly pedi: | 
celled perianth, twisted style, binate paleæ of the male receptacle, which are also clavate 3 
and dilated at the base, white papillose (male) perianth, longer filament, globose synema - 
and globose pollen. It is also added, that the anthers are 2-celled, and dehisce differently, 
leaving a triangular opening between them, and that the filaments are free immediatel 
below the anthers. | 
With regard to these points, I find the capitulum if anything more depressed in the 
Mexican plant and in Liebmann’s accurate figure of it, than in Richard’s drawing of the 
Brazilian, or than in most of my specimens either of the Brazilian or Colombian plant. 
The stem (peduncle) varies extremely in length, from 4 an inch to 8 inches, and con- 
siderably even on the same rhizome. The perianths of Mexican specimens are much 
longer than those of Liebmann's figure, and they are of the same length as those of my 
Brazilian specimens, though shorter than in Richard’s or Martius’ figures. The styles of 
the Mexican plant are very slightly twisted, and that from left to right, not the opposite 
way, as represented in Prof. Liebmann's figure; and there is the same twist in Mr. Purdie’s 
and in some of the Brazilian specimens. The perianths seem constantly papillose, though 
varying in degree with age, drying, and other less obvious causes, Globose pollen is the 
so extremely short, that it appears impossible to draw a character from it; the synema. 
varies in form, according to its age, and that represented in the figure of 7. Mexicana 
. entirely agrees with Brazilian individuals; and finally, the anthers of all, though 4-celled 
in their early and perfect state, become 2-celled previous to dehiscence, by the contraction 
of the septum. I therefore feel justified in referring the Thonningia Mexicana to 
Langsdorffia hypogæa. 
. The parasitism of Langsdorffia is remarkable: the dichotomously branching rhizom 
appear most frequently to corrode, as it were, the bark of the roots they encounter, which 
they even sever, and then enclose the end that remains attached to the parent plant: the 
root swells considerably at the junction, and appears to send prolongations of wood into 
the rhizome of the parasite, which run along its axis for several inches; but though 
there is an intimate union between the wood of the root and the cellular tissue of the 
parasite, there seems to be no blending of their vascular systems. The rhizome also 
invariably swells at the junction, but does not branch from that point, as is often the case 
with Helosis. Both Richard and Martius represent rootlets as given off from the rhizome 
at a considerable distance from any parasitic union; but I do not find such in any of my 
Ru — have any other Balanophoreæ rootlets, though at the junction of root and 
parasite similar rootlets to those figured by Martius are often given off by the root, and 
these being partially enveloped by the parasite, appear to proceed from it. Martius an 
Langsdorff further say that the plant grasps other roots by means of these fibres, and 
