86 POPULAR SCIENCE MONTHLY 



plant life growing in bodies of still water, or even in running water 

 where the bottom will permit the rooting of the plant. But in addition 

 to this evident growth there is an enormous development of life, micro- 

 scopic or transparent and invisible except when collected and studied 

 by proper methods, which, in rapidity of growth and amount of mass 

 may far outclass the visible portion. Some of this becomes apparent as 

 green scum or as floating masses when its growth exceeds the capacity 

 of the aquatic animals to consume it. Sometimes these minute algae 

 become a great source of annoyance in water supplies if for any reason 

 their multiplication is unchecked, since they give offensive odors and 

 taste to the water. 



It has been estimated that the rate of development in some of 

 these organisms is such that the possible progeny of one individual 

 would suffice to fill all the waters of the globe in less than a week. 



This is significant to us here simply as showing the enormous pos- 

 sibility of these organisms in utilizing water and air in the formation 

 of vegetable substance, which substance may, with proper utilization, 

 be transformed into fertilizing agents for the production of valuable 

 plant crops or into animals having direct commercial value. To under- 

 stand this process, let us consider for a moment the relations existing 

 among aquatic organisms. The algae may be considered among the 

 more simple and these develop with only water and air or the other 

 inorganic contents of water, but they furnish food for an innumerable 

 host of microscopic animals such as amcebas, rotifers, etc., and these 

 in turn are fed upon by others, such as microscopic Crustacea, which 

 again form an important part in the diet of young fishes. These, when 

 grown, or after furnishing the basis of food for other larger species, 

 may reach our tables as human food. This, however, is but one line of 

 transformation, as we have fishes of very different habits utilizing dif- 

 ferent kinds of aquatic life as food. 



Where the life taken from the water does not balance the produc- 

 tion, or where this product is not drained off into the sea, the accumu- 

 lation of organic debris forms at the bottom a mass of richest organic 

 matter, which by its decomposition may in a large part result in marsh 

 gas, and in this form escape into the air. 



Having indicated the possibility of an unworked phase of agricul- 

 ture, or aquaculture, let us now turn to some of the possible lines of 

 development in this field. 



We have in America practically no established system of cropping 

 our water areas. It is true that some progress has been made in the 

 sponge farming of Florida, and oyster farming in Rhode Island, Con- 

 necticut, Virginia, North Carolina and Louisiana, but even these need 

 further development to utilize the natural possibilities. 



But so far as fresh-water culture goes, there is scarcely a begin- 



