Even if any consideration of final causes be excluded; even if it be not permitted to suggest that the high and constant reproductive force in vegetables and animals has been ordered to enable them to subserve the uses of man, and that therefore the pressure of the lower forms of life against subsistence does not tend to show that it must likewise be so with man, “the roof and crown of things;” yet there still remains a distinction between man and all other forms of life that destroys the analogy. Of all living things, man is the only one who can give play to the reproductive forces, more powerful than his own, which supply him with food. Beast, insect, bird, and fish take only what they find. Their increase is at the expense of their food, and when they have reached the existing limits of food, their food must increase before they can increase. But unlike that of any other living thing, the increase of man involves the increase of his food. If bears instead of men had been shipped from Europe to the North American continent, there would now be no more bears than in the time of Columbus, and possibly fewer, for bear food would not have been increased nor the conditions of bear life extended, by the bear immigration, but probably the reverse. But within the limits of the United States alone, there are now forty-five millions of men where then there were only a few hundred thousand, and yet there is now within that territory much more food per capita for the forty-five millions than there was then for the few hundred thousand. It is not the increase of food that has caused this increase of men; but the increase of men that has brought about the increase of food. There is more food, simply because there are more men. Here is a difference between the animal and the man. Both the jay-hawk and the man eat chickens, but the more jay-hawks the fewer chickens, while the more men the more chickens. Both the seal and the man eat salmon, but when a seal takes a salmon there is a salmon the less, and were seals to increase past a certain point salmon must diminish; while by placing the spawn of the salmon under favorable conditions man can so increase the number of salmon as more than to make up for all he may take, and thus, no matter how much men may increase, their increase need never outrun the supply of salmon.