MDTUTE ORGANISMS. 141 



life by promoting the growth and multiplication of other tribes 

 equally minute in dimensions. 



I do not know that man has yet endeavored to avail himself, 

 by artificial contrivances, of the agency of these wonderful archi- 

 tects and manufacturers. We are hardly well enough acquainted 

 with their natural economy to devise means to turn their industry 

 to profitable account, and they are in very many cases too slow 

 in producing visible results for an age so impatient as ours. The 

 over-civilization of the nineteenth century can not wait for wealth 

 to be amassed by infinitesimal gains, and we are in haste to specu- 

 late upon the powers of nature, as we do upon objects of bargain 

 and sale in our trafficking one with another. But there are stiU 

 some cases where the httle we know of a life, whose workings 

 are invisible to the naked eye, suggests the possibility of advan- 

 tageously directing the efforts of troops of artisans that we can 

 not see. Upon coasts occupied by the corallines, the reef -building 

 animalcule does not work near the mouth of rivers. Hence the 

 change of the outlet of a stream, often a very easy matter, may 

 promote the construction of a barrier to coast navigation at one 

 point, and check the formation of a reef at another, by diverting 

 a current of fresh water from the former and pouring it into the 

 sea at the latter. Cases may probably be found, in tropical seas, 

 where rivers have prevented the working of the coral animalcules 

 in straits separating islands from each other or from the main- 

 land. The diversion of such streams might remove this obstacle, 

 and reefs consequently be formed which should convert an archi- 

 pelago into a single large island, and finally join that to the 

 neighboring continent. 



Quatrefages proposed to destroy the teredo in harbors by im- 

 pregnating the water with a mineral solution fatal to them. 

 Perhaps the labors of the coraUine animals might be arrested 

 over a considerable extent of sea-coast by similar means. The 

 reef-builders are leisurely architects, but the precious coral is 

 formed so rapidly that the beds may be refished advantageously 

 as often as once in ten years.* It does not seem impossible that 



* The smallest twig of the precious coral thrown back into the sea attachea 

 itself to the bottom or to a rock, and grows as well as on its native stem. 



See an interesting report on the coral fishery, by Sant' Agabio, Italian Con 

 flul-General at Algiers, in the Bollettino Consolare, published by the Depart 



