Germination of the Seeds of Aquatic Plants. 345 
wet mud, influences, however, that would also greatly differ 
under natural conditions. A considerable number of special 
experiments were also made on the effects of light, of drying, 
of ice, of the removal of the seed-coverings, and of the influ- 
ence of sea-water immersion. Their addition to the Table 
would not only have swelled it to twice its size, but would 
have obscured its principal purpose, that of exemplifying 
the postponement of germination. Their results, however, 
will be given in the text when dealing with the individual 
plants; but those relating to temperature will remain for 
future treatment, the errors likely to spring from this source 
being guarded against by preserving the same thermal con- 
ditions in all cases of special experiments. 
With regard to the influences affecting the germination of 
Nuphar luteum and Nymphea alba, which stand first on the 
list, it may be at the outset remarked that the seeds of the 
first plant are less Hable to decay in water than those of the 
second. During the first two years of Experiment 2, only 
24 per cent. of the Nuphar seeds rotted. In Experiment 5, 
about 6 per cent. of the Vymphea seeds decayed in less than 
twelve months. It will be observed in the Table that the 
seeds of Vymphea alba germinated in much greater number 
in the first year than did those of Nuphar lutewm, and that 
the last-named plant is better able to defer the germinating 
process over a series of years. Drying soon deprives the seeds 
of both plants of their germinating capacity. Various experi- 
ments on seeds that had been dried, in each case, for periods 
ranging from two to fifteen months gave no results, the seeds 
when examined being in all stages of decay. This is doubtless 
due to the circumstance that they readily lose their moisture. 
The seeds of Nuphar lost 30 per cent. of their weight in 
nine days and 50 per cent. in a month, the subsequent loss 
of weight after many months’ drying being very slight. 
The following experiment was made on Nuphar luteum 
with the view of determining the influence of different 
degrees of light on germination. A large number of seeds 
were divided equally, and placed, on December 9th, in four 
vessels of water. Two vessels were placed in a greenhouse - 
and two in a room; whilst in each case the two vessels were 
