A SPRIG OF WATER CROWFOOT. 45 



new leaves which sprout in the air meet with 

 abundance of carbon and sunlight on every 

 side ; and we know that plants grow fast 

 just in proportion to the supply of carbon. 

 They have pushed their way into an unoc- 

 cupied field, and they may thrive apace 

 without let or hindrance. So, instead of 

 splitting- up into little lance-like leaflets, they 

 loll on the surface, and spread out broader 

 and fuller, like the rest of their race. The 

 leaf becomes at once a broad type of crow- 

 foot leaf. Even the ends of the submerged 

 leaves, when any fall of the water in time of 

 drought raises them above the level, have a 

 tendency (as I have often noticed) to grow 

 broader and fatter, with increased facilities for 

 food ; but when the whole leaf rises from the 

 first to the top the inherited family instinct 

 finds full play for its genius, and the blades 

 fill out as naturally as well-bred pigs. The 

 two types of leaf remind one much of gills 

 and lungs respectively. 



But above water, as below it, the crow- 



