Fission-products of a Parasitic Alga. 179 
small but long and slender diatoms like Nitzschiv, while 
fig. 3, C, D, contained broader and more ovoid organisms of the 
Navicula type. 
It occasionally happens that the spores of the Chloro- 
chytrium force their way from a closely packed space in 
which they have been produced, whence exit is not easy, in 
between various of the contiguous sub-epidermal cells, and 
occasionally in these situations I have also found diatoms. 
Spores in these situations between the spherical cells are 
shown on the right side of fig. 1, D. 
There is another point of much interest to be mentioned. 
Sometimes one of the epidermal cells, of zigzag outline, 
will here and there be found filled by a light green alga 
having the appearance of being a species of Chlorochytrium 
(fig. 5, A). Other of these cells may be found in which 
such bodies seem about to undergo fission into several smaller 
cells (fig. 5, B), and others still in which the original cell 
has divided into small green ovoid products (C) or into a 
number of more minute zoospores. In one case such zoospores 
were seen to have assumed a yellow colour and some of them 
seemed to be elongating, as was the case with some of the 
segments shown in fig. 5, D. Many other of these isolated 
epidermal cells have been found containing either small ovoid 
diatoms only (fig. 5, F) or a mixture of such diatoms with 
green fission-products as in fig. 5, E—just as I have found 
the two kinds of bodies associated in the much larger sub- 
stomatal spaces. 
The diatoms in the epidermal cells are always small, com- 
monly of about the same size, but not invariably so, and 
mostly having the appearance of being minute Navicule. 
How the Chlorochytrium spores obtain an entry into the 
epidermal cells I am unable to state; but being actively 
motile, it would clearly be much easier for them to get in 
than for the diatoms to do so. 
It seems most probable that it is the spores of Ch. Any- 
anum which infect these epidermal cells, and it seems possible 
that they may penetrate them from a substomatal space, as I 
have often, though by no means invariably, found such 
infected epidermal cells just over, or by the side of, one of 
these spaces. 
What interpretation is to be given concerning the associa- 
tion of the diatoms with the Chlorochytrium fission- products ? 
Only two possibilities seem to present themselves :— 
(a) The diatoms have, like the alge, obtained entry to the 
subepidermal spaces through the stomata. Ae 
