172 



ANIMALS OF LAND AND SEA 



line, however, is easily translated from a menace into a distinct 

 advantage; animals simply attach themselves firmly to sea- 

 weeds, stones, or other 

 objects, and let the 

 water do the work of 

 bringing food to them. 

 On land the most 

 successful plants are 

 the flowering plants 

 which grow by form- 

 ing a series of units 

 one above the other 

 called phytons, by the 

 multiplication of these 

 units producing a ro- 

 sette of leaves or a tall 

 or branching leafy stem 

 and thus exposing the 

 maximum green sur- 

 face to the sunlight 

 and the air. 



The sea water being 

 charged with nutrient 

 particles throughout, 

 it is obvious that in 

 the shallow regions 

 any animals which are 



able to attach them- 

 selves and to produce 

 in the same way as do 

 the flowering plants 

 an indefinite series of reduplicated units each more or less per- 

 fect in itself would be able to avail themselves to best advan- 

 tage of the food materials drifting here and there and all around 

 about them. 

 Attached animals, particularly animals that grow and look 



Figs. 494-496. Two deep-sea crabs 

 and a Jelly-fish. 



For explanations of the figures see p. xxvi. 



