A SUBAQUEOUS CITY. 145 



duct of great commercial importance. Perhaps no 

 more striking illustration could be found of the 

 truth of the adage that "union is strength" than 

 here in these two lowly, and, in their isolated 

 individuality, helpless beings, yet who, in their 

 combination, raise themselves in the scale of life, 

 and produce a structure combining all the func- 

 tions of higher and more complex organisms ; 

 having no stomach, yet perfect digestion and assi- 

 milation; no heart, yet free and full circulation; 

 no lungs or gills, yet complete aeration and re- 

 spiration ; no manipulatory organs, yet building 

 up a structure combining all the requisites of 

 strength and endurance, with the most wonderful 

 lightness and flexibility. 



The Flagellate cells are apparently the most 

 active workers, while the Amoeboids form the 

 ground-work of the colony, yet also aiding by 

 their expansions and contractions in the general 

 movement of the currents through the several pas- 

 sages and the elevation or depression of the crater- 

 like vent. Nerve, muscle, and reproductive work 

 belong principally to the Amreba, as also the secre- 

 tion and development of the structureless external 



