SECRETARY'S REPORT. 141 



as waste material is not simply a waste to liim, Ijut is eitlier a 

 poison to the air or capa])le of soon becoming so. The carl)omc 

 acid from the kings and all the excretions formed l)y the waste 

 of tissues fill the air with deadly poisons. . But upon all the waste 

 materials rejected l)y the animal system, the plants live. They 

 sweep the carbonic acid from tlie air by their multitude of 

 leaves, draw it from the soil by a thousand rootlets, and gather 

 up the various organic compounds as they are ready to change 

 to poisons, and in the wonderful laboratory of their leafy tissue, 

 they unlock and re-combine the elements, giving back to us in 

 woody fibre, in starch and sugar, in the nutritious grains and 

 delicious fruits, those very materials which but for them would 

 have generated deadly disease. They then throw Ijack from the 

 leaves the liberated oxygen in that active form known as ozone, 

 in which it is most efficient as a purifyer of the air. Not only 

 do the plants thus stand ready to save animals from the eifect 

 of their own poisoning influence upon the air, but they seem to 

 have committed to them the task of protecting animal life from 

 the poisons produced by general decomposition, both by gather- 

 ing up the poisons, and also by some of them showing hy 

 their very presence the existence of poisons, and thus warning 

 intelligent man of his danger. 



On the stagnant pool the green film gathers, to many appear- 

 ing the cause of disease, but in reality the safeguard which 

 nature has prepared ; a thin veil, with cliemical power, which 

 she has spread over such places to gather up and condense a 

 portion of the poisons, and to be a token of their presence. 

 Around our southern swamps she has hung the long moss in 

 rich festoons upon the trees, and woven the thick barrier of 

 climbers, through both of which much of the air is strained. 

 These plants, then, are more than a sign that poisons are gener- 

 ated there ; they feed upon and destroy them. 



In studying these relationships, it soon becomes apparent that 

 the yegetable kingdom is in general subservient to tlic animal. 

 The lower is made to serve the higher. The plants are directly 

 or indirectly the support of all animal life. No animals, unless 

 it be some of microscopic size, have power to live upon inorganic 

 matter. If they have power to assimilate it at all, they have no 

 power to assimilate a sufilcicnt portion to sustain life. 



