SOCIAL AND POLITICAL ECONOMY. 



199 



One of the most suggestive facts illustrative of 

 the economic policy of plants is afforded by various 

 species of the genus Rammailus. It is dwelt upon 



Fig. 77. — Ran7C7ic7ihis tripartics, with Fig. 7S. — Raniinciilus droxiettii, 

 abbreviated ordinary leaves. showing entire absence of ordin- 



ary leaves. 



at length by Mr. Grant Allen ; but convenient allu- 

 sion suggests itself here. Water cannot and does 

 not contain so much carbonic acid as the atmosphere 

 — hence the filiform or thread-like shapes of the 



