340 Groom. — On Thismia Aseroe ( Beccari ) 
but as the hypertrophy is particularly on the side towards the 
nucleus, the thin continuation of the original hypha (i.e. the 
apical part) appears to spring from the young bladder at 
a point close to the insertion of the original slender portion 
of the hypha. The bladder gradually assumes a spherical 
form. At first it is filled with a densely pink-staining mass 
of cytoplasm with many nuclei. But as it attains larger 
dimensions vacuolation sets in. The bladder is now mature, 
and the further changes in it are associated with its waning 
vitality and death. Either the natural movements of the 
cell’s protoplasm, or movements associated with the local 
hypertrophy of the hypha, cause the host’s nucleus to shift 
its position in the cell. The young slender continuation of 
the original hypha now bends towards the cell-nucleus, and 
applying itself to the latter proceeds to form a second bladder. 
In the meanwhile great changes are taking place in the first 
bladder. Its protoplasm loses its staining intensity, diminishes 
in amount, and at the same time there is deposited in it 
a homogeneous yellow substance in which are rod-like bodies, 
which remind one of the regular rod-like c bacteroids 3 in 
leguminous tubercles. This deposit appears always to com- 
mence at the proximal part of the bladder, and is not 
a product of the metamorphosis of the cell-wall, though it 
lies close within the wall and sooner or later is absolutely in 
contact with it. This substance gradually increases in size, 
the walls of the bladder collapse, and finally nothing remains 
but a shrunken wall covering a mass of homogeneous substance 
coloured by a yellow oil-like liquid, and containing numerous 
rod-like bodies. The older thin portion of the hypha shrinks 
too, and the yellow substance seems to block the connexion 
between its lumen and the thin portions of the hypha. So it 
is altogether inconceivable that any considerable conduction 
of liquids can take place along these thin portions of the 
hyphae. The second bladder soon passes through the same 
changes as the first, and a third bladder, or even a fourth and 
fifth, may be formed and repeat the process. But sooner 
or later the hypha passes through the cell -wall and enters 
