A Parasite of Stigmarian Rootlets. 67 
Springing from this outer secondary tissue and in apparent 
organic connection with it is the large cylindrical cell ( li.c .) alluded 
to above, which lies in a deep pit-like depression of the outer cortex. 
The passage through the outer cortex is considerably wider than 
the cylindrical cell, and is lined Jiy the remnants of dead cells which 
seem to have been destroyed by the outward growth of the hyper¬ 
trophied inner cell of the cortex. The latter cell was therefore 
probably of greater width than is now shown in the preparation, and 
may be supposed to have undergone considerable collapse. This 
view is borne out by its appearance, which, especially in the central 
contracted region, is suggestive of a shrunken cell. Here it is only 
^0 mm. in diameter, while at its apex it is nearly twice as broad. 
The length of the cell is ^ mm., and at its apex is a wide aperture 
through which the bulk of the contents would seem to have escaped 
before mineralisation, and this would be a sufficient cause for the 
contraction which has evidently taken place in this cell. It seems 
also to have contracted slightly in length as it does not now reach 
to the outermost limits of the outer cortex. 
The nature of the contents of this cell may, perhaps, be 
indicated by what are I think possibly remnants thereof. Half-way 
down the hypertrophied cell there is a fairly large round body not 
•* 
unlike a very thin-walled spore (20/-/,), and at the base of the cell a 
shrunken membrane would seem to have surrounded another spore. 
One or two faint indications of other spore-like bodies can be seen 
in other focal planes. Remains of other contents are indicated at 
the base of the cell by fine thread-like granulations, but their nature 
is too uncertain to allow of identification. The appearance of an 
oblique wall crossing the hypertrophied cell near its distal end is 
due to a crack in the matrix and does not represent any cell- 
membrane. As the cell is therefore open to the exterior it might, 
perhaps, be argued that the spore-like bodies had entered from the 
outside, or were due to some fungus which might have developed 
its spores in this convenient cavity without having preyed upon the 
plant. Such an explanation might be sufficient if the cell in question 
were the normal part of a Stigmarian rootlet. As it is, however, 
this hypertrophied cell itself requires explanation. 
Two alternatives are suggested by the occurrence of spore-like 
bodies within the cell, and by the formation of secondary tissue 
within the root with the apparent object of limiting the ravages of 
some parasitic organism. The large cylindrical cell might either be 
a fungal sporangium or an hypertrophied cell of the rootlet acting 
