83 
Cutler ia multi ft da ( Grev . ). 
On adding a fresh supply of filtered water, another week 
gave a second similar crop of germinating oospheres, and 
a third week yet another, thus confirming Thuret’s original 
observations. 
Several distinct cultures, some containing fragments of 
female thallus, still producing oospheres, which had been 
growing in filtered water in the laboratory since August, 
others containing freshly discharged oospheres only, were 
made towards the end of September. In all cases germination 
proceeded directly and quite normally, although slower than 
in the case of the first crop obtained in August, and far slower 
than in the experiments of Falkenberg, who states that his 
fertilized oospheres produced a plant of 3-4 cells in the 
first twenty-four hours, whereas the Plymouth cultures in 
September did not do more than this in the first week. It is 
probable, however, that this rate of growth varies directly 
with the temperature. 
Finally, separate cultures, from small pieces of female plants 
collected on September 21, were made on October 12, and 
brought to Oxford and kept in a sunny window. In all cases 
germination again took place normally ; in three days 
sufficient oospheres had collected on the side nearest the light 
to form a visible film. The majority of the oospheres were 
covered with a well-marked membrane and many had already 
put out the first rhizoid. The temperature was low (14°) and 
the weather dull, but after two days of bright sunshine the 
plants increased to about five cells and a long rhizoid, and by 
October 25 they formed well-grown embryos in which 
segmentation was rapidly proceeding (Fig. 13). 
At the end of three weeks (November 1), the culture- 
vessels having latterly been standing in bright sun for a few 
hours every day, an immense number of young plants in all 
stages of development were to be seen, the small piece of 
thallus in the culture continuing to give off oospheres. The 
oldest plants showed the * foot-embryo ’ now at its maximum 
size, but with so far no formation of dorsiventral lobes (Fig. 14). 
That is to say, the germination of these unmistakably 
