14 JANUARY 



there was danger of the whole lake being turned 

 into a morass, so dense and all-prevailing are the 

 masses of vegetation; but experience has shown 

 that this strange exotic disappears as quickly as it 

 comes. When first introduced to a sheet of water, 

 it multiplies with prodigious rapidity, and threatens 

 to choke all the channel; but in two or three 

 seasons the soil becomes exhausted, the weed shrinks 

 into a verdant carpet at the bottom, till, after the 

 lapse of ten or a dozen years, the soil has recovered 

 strength to send up another vast crop, which passes 

 away in like manner as the first. 



The introduction of this weed (Elodea canadensis) 

 into European waters is part of the romance of 

 botany, It is said that a Cambridge professor, having 

 received some specimens from a botanical friend in 

 Canada, incautiously left them in his wash-hand 

 basin, whence they were emptied by an over-diligent 

 housemaid into that bourne whence no specimen 

 returns. A few years later, beds of a weed new to 

 English botanists were found to have taken posses- 

 sion of certain reaches in the Cam, and great was the 

 throwing up of scientific hats at this notable addition 

 to the British flora, which received the name Ana- 

 charis alsinastrum. But in fulness of time the 



