Triglochin maritimum , L. 87 
lignified to such an extent that the lumina become almost 
obliterated ; in this manner the extremely hard sclerotic cells 
already referred to become differentiated. 
The course of the leaf-trace bundles in the rhizome calls 
for no special comment, inasmuch as it somewhat resembles 
the type exemplified by the Palms, that is to say, the bundles, 
after coming in from the leaves, travel obliquely through the 
cortex to the central cylinder, where they curve towards the 
centre and then pass out to the periphery. In Triglochin 
the course of these bundles is very complicated, inasmuch as 
numerous branchings and anastomoses take place. 
A transverse section of the rhizome shows numerous small 
bundles arranged in the peripheral part of the central cylinder. 
These are connected by horizontal commissures to form 
a reseau radicifhe such as obtains in many Monocotyledons. 
These peripheral bundles run roughly in a longitudinal direc¬ 
tion ; but in the region of insertion of a root they are united 
transversely, so that a root may be connected with at least 
one-half of the total number of bundles, of which there may 
be as many as twenty-five to thirty. 
One feature of interest connected with the anatomy of the 
plant under consideration lies in the occurrence of occasional 
cell-divisions recalling those of a cambium. These cambia 
were not at all common ; the best example seen is represented 
in Fig. 3, PL VI. From this figure it will be seen that the 
cambium is well marked and has been formed from the peri- 
cycle ; it is situated opposite a young bundle on its outer side. 
The other examples seen were cambial divisions in single 
pericyclic cells ; they were not sufficiently developed, however, 
to throw much light upon the subject. 
The part of the rhizome from which the section containing 
this cambium (Fig. 3) was cut was not by any means young, 
as is seen by the greatly thickened endodermis ; unfortunately 
it cannot be said exactly how old this part of the rhizome was, 
inasmuch as the portion was an isolated piece of stem. There 
were no indications of the cambium being due to pathological 
effects, the cells around being, as far as could be judged from 
