Thiselton-Dyer. — Morphological Notes. 753 
as remarkable. Every plant without exception was rooted at 
the point from where the groups of thorns of the Cactus grow, 
and on the tipper side of that point. I was unable to find one 
single instance where the Quintral sprang from either the 
furrow in the Cactus, or from the lower or lateral side of the 
groups of thorns.’ 
I was curious to ascertain the nature of the external coat 
of the haustorium. This is indeed all that represents it, as the 
internal tissues, which must have been soft, have all but com- 
pletely decayed, leaving a mere inflated and hollow shell ; 
and the investigation offered little promise of yielding any 
result of interest. I am greatly indebted to Mr. L. A. Boodle, 
F.L.S., for kindly making the attempt, with results as interest- 
ing as they were unexpected. He has kindly permitted me 
to add his observations in the following note. 
Histology of the Haustorium. 
By L. A. Boodle, F.L.S, 
The branched body, of thalloid form, which was immersed 
in the cortical tissues of the Cerens , and which is seen in 
Fig. 2, might be thought at first to consist of nothing but the 
haustorial apparatus of the Loranthus. Microscopic examina- 
tion, however, showed that its more external tissues were 
composed entirely of a periderm, whose characters proved it 
to belong to the host-plant. 
The periderm encloses a central core of tissue, which must 
consist of a haustorium of the Loranthus , together with a certain 
amount of injured cortical tissue belongingto the Cactus ; but 
unfortunately, in most places, everything within the periderm 
was found to have become withered or disorganized into a 
brown or nearly black mass, in which structure could not be 
recognized. Fig. 3 is a photograph of a transverse section of 
one of the small branches of the specimen. The periderm is 
clearest on the upper and lower sides in the figure, and is seen 
to consist of two kinds of tissue, thick- and thin-walled cells 
forming separate zones ; a. and c. are two bands of the thick- 
