Dar bishire. — On Actinococcus and Phyllophora. 263 
angles to the long axis of the fertile filament. The spore mother- 
cells measure iax i6/x 5 the four nuclei being formed before the 
formation of cell-walls gives rise to the four tetraspores. 
The tetraspores themselves are spherical in shape, and 
when escaping at maturity they measure 10-13 /x in diameter. 
They are surrounded by a very thin membrane, their cell- 
contents consisting of a very finely divided rhodoplastid and 
numerous starch-grains. 
On arriving at maturity the nemathecia break up, the 
tetraspores are set free and presumably germinate. It is 
impossible as yet to say what actually is the fate of these 
tetraspores of Actinococcus subcutaneus , after they have been 
set free from the parasitic nemathecium. Do they germinate 
on another host and there form sexual plants with antheridia 
and procarpia? 
The tetraspores ripen in December and January and shortly 
after are discharged from the nemathecia, some of the latter 
apparently continuing to vegetate for some time. With the 
appearance of the spermophores in the following autumn, we 
again find the parasite entering the host-plant. What have 
the spores been doing in the meantime? From what has 
already been said, it is not unlikely that what we see 
germinating on Phyll . Brodiaei in the autumn is really 
a carpospore. 
It has been possible to follow out the germination of the 
tetraspores of our species of Actinococcus. Briefly the results 
obtained were the following ( 2 , pp. 25 - 27 , Fig. 32 , 33 ). The 
tetraspores, derived from the nemathecia of Actinococcus 
subcutaneus , were sown on sterilized and purified parchment- 
paper. The whole was put in a small glass vessel filled with 
filtered seawater. Several cultures were started. The spores 
germinated, and in parts remained in a living condition for 
nearly two years. The products of germination took the 
form of small protonema-like organisms. The largest of 
these consisted of uniserial filaments and larger aggregations 
of cells, which at the time I took to be the rudimentary basal 
attachment-disks of Phyll. Brodiaei : it consisted altogether of 
