428 Scientific Intelligence. 
III. Borany anp Zootoey. 
1. For what purpose were plants created ? (addressed to Prof. Dana.) 
— Plants furnish all the food upon which animals live. ants, by de- 
composing carbonic acid, &c., purify the air which animals breathe. In 
which of these offices may we say that the vegetable kingdom fulfills 
its essential purpose? In your admirable exposure of the character 
and tendency of Prof. Tayler Lewis’s work, you take the view that the 
essential object of the vegetable creation is to purify the atmosphere 
for the breathing of animals, and assert that its use in providing food 
for animals is only incidental, or ‘ concomitant.’ 
so sound and able, and because it proceeds from such very high 
scientific authority, that] am induced to call your attention to this 
questionable point, not without the hope that you may see cause to 
correct or qualify the statement. 
That the office of plants in the economy of the world is, not so 
much to purify the air for animals, as to supply them nourishment, 
may be argue 
Ist. From the nature of the operation in which oxygen gas is libera- 
from its parts, and continue to exist; or the evolution of the oxy- 
gen gas necessarily separated in the process, and which has to be got 
rid o 
It is in this deorydizing and organizing operation, no doabt, that the 
i i hat the pu 
rom considering the kind and the degree of the dependence 
of the animal creation upon these two results of vegetation, namely, 
the vegetable matter produced, and the oxygen gas liberated. Now, 
For vegetable matter, so produced furnishes the whole food and fabric 
of animals. Without it «animal life could not have existed at all ; and 
were its production now to be suspended, all the herbivorous and theo 
‘the carnivorous races would perish almest at once. On the other hand, 
the amount of the dependence of animal life upon the disengagement 
