EXTERNAL CONFIGURATION OF PLANTS. 175 



IS drowned, or a fish taken out of the ^vater dies. 

 A land animal is incapacitated for an aquatic exist- 

 ence, not only by the possession of lungs instead of 

 gills, but also by the shape of its body and the 

 form of its limbs. If the ancestors of existing 

 marine mammalia — the whales and porpoises — were 

 originally land animals whose descendants have 

 been si3ecialised for an aquatic mode of life, then it 

 would appear that the transformation had been 

 accomxDlished witliout any radical change in the 

 organs of respiration ; but the external form of the 

 body and limbs has undergone extensive alteration. 

 The bodily contour is thus of greater importance 

 than might have been supposed. "Nature," says 

 the poet, " hath framed strange felloAvs in her time;" 

 but perhaps, if we knew the difficulties with which 

 each " fellow " has to contend, his physiognomy 

 might not seem so strange after all. A mermaid is 

 a natural enough conception, if she be supposed to 

 live with the ui:)per portion of her body always in 

 the air and the lower part always submerged. Sup- 

 pose such a form entirely submerged, or entirely out 

 of water, and it becomes unstable and grotesque. 

 There is a regulation uniform in the domain of 

 Neptune, and all who acknowledge the Sea-god's 

 sway must conform to the fashion of his court. 

 This obligation is quite as imperative for plants as 

 for animals. Consider the effect of making a 

 marine plant change place with a terrestrial one. 

 The sea-weed finds all the food it requires in the 

 surrounding water ; it has no need therefore of a 

 root to absorb water and mineral salts. Accordingly, 

 were we to transplant it into a garden, it would be 

 unable to extract sufficient water or mineral sub- 

 stances from the soil to support its existence. The 

 branched base of a sea-weed is not a root in this 

 sense at all : it merely serves to fix or anchor the 

 plant, and thus prevent the waves from dashing it 

 to pieces on the shore. Again, marine Algce have 

 no stems, in the ordinary sense, and cannot as a 



