196 THE PLANT WORLD. 



minate. giving' rise to a new generation of pelagic organisms, 

 which by their prohfic division are able in a few days to domi- 

 nate completely a piece of water. 



The pelagic plants form the food of the animal plankton ; 

 these, again, are devoured by their larger brethren, which are the 

 main source of nutrition for the smaller fishes. The larger fish 

 are mostly carnivorous, feeding on smaller individuals of their 

 kind. The organic matter of the pelagic plants thus gradually 

 travels from one organism to another until it comes to form part 

 of the body of the large aquatic animals ; it passes through a 

 series of incarnations before being returned to the water in the 

 form of excrement or products of decay of dead animal and vege- 

 table bodies. This organic matter is built up by the pelagic 

 plants from simple inorganic salts and from carbon dioxide dis- 

 solved in the water, and these latter substances are thus changed 

 into a form which makes them available to ac^uatic fauna. All 

 the organisms of the latter, as, indeed, all the animals of the 

 world, are ultimately herbivorous. Without some kind of plant 

 growth a piece of water must remain a lifeless, dead mass, unpop- 

 ulated, and a thing apart from the living world around it. The 

 presence of vegetation immediately transforms it into a throbbing 

 imiverse, full of energetic life, exhibiting complex interrelation- 

 ships, and connects it with the remaining parts of our universe. 

 The most important element of the vegetation from this point of 

 view, however, is the phyto-plankton. and a piece of water with 

 plenty of pelagic plants is sure to form a good breeding place 

 for fish and other aquatic animals. — Nofurc, London, March 22, 

 1906. 



THE JARDIX DES PLANTES BEFORE AND DURING 

 THE REVOLUTION.* 



In the Edinburgh Rcviciv for April, 1906, an anonymous writer 



has given us a charming glimpse into the Jardin des Plantes of 



two centuries ago. 



" A long garden, lying low and flat for the most part, planted with 

 inconsiderable trees, it rises imperceptibly from the left bank of the Seine 

 to the further eastern slope of the JNIontagne Ste. Genevieve; crowned 



* From the Edinburgh Rcz'icu'. ■ 



