THE AMERICAN WATER WEED. 133 
until their entire cessation marks its entire exhaustion, viz.,— 
death. What we call “life” seems indeed to depend upon the 
action and reaction upon each other of two distinct particles of 
protoplasm, endowed with the power of acting upon each other 
in a manner which may be compared to effervescence. This 
period of effervescence—life, continues so long as any difference 
remains either in potentiality, construction, or constitution 
between the two interacting particles, and may also be greatly 
prolonged or shortened by external conditions. So soon as they 
cease to differ, life ceases, and we have death. 
Therefore the probability is that unless male plants of 
Anacharis occur in other parts of the country, or the plants 
become more truly hemaphrodite, it will continue its eccentric 
course until it has exhausted its present abnormal vitality, and 
then either become rare or die out in Great Britain altogether. 
If the male plant should spread, it will most probably never die 
out, but its rapid increase will be effectually checked, and its 
vegetative powers be greatly reduced by the demands made upon 
its strength incidental to the development of seeds. The old 
tenants of our waters will then have a better chance to defend 
themselves in the struggle for existence, and may probably 
finally oust the invader altogether. 
