JOURNAL OF THE ANTHROPOLOGICAL SOCIETY.

...there are causes in nature that would stop any further physical change once certain conditions were met—this does not even make such progress unlikely, if there are any general arguments to be presented in its favor. I believe such a cause does exist, and I will now try to explain its nature and how it works.

To make my argument understandable, I must briefly explain the theory of "Natural Selection" proposed by Mr. Darwin, and its power to modify the forms of animals and plants. The main feature in the reproduction of organic life is a close general resemblance combined with more or less individual variation. A child resembles its parents or ancestors quite closely in all its traits, whether they are defects or beauties. Generally, a child looks more like its parents than like any other individuals; yet children of the same parents are not all identical, and they often differ significantly from their parents and one another. This is equally true of humans, all animals, and all plants. Furthermore, individuals do not differ from their parents in only a few specific details while remaining exact duplicates in every other way. They differ from their parents and each other in every detail: in shape, size, color, and the structure of both internal and external organs. They vary in those subtle traits that create differences in constitution The physical makeup or inherent health and temperament of an individual., as well as in the even more subtle ones that lead to changes in mind and character. In other words, individuals from the same lineage vary in every possible way, in every organ, and in every function.

Now, health, strength, and long life result from a harmony between the individual and the environment that surrounds it. Suppose that at any given moment this harmony is perfect. Imagine an animal that is perfectly suited to catch its prey, escape its enemies, withstand the inclemencies Harsh or severe weather conditions. of the seasons, and raise many healthy offspring. But then a change occurs. For instance, a series of cold winters sets in, making food scarce and bringing in a migration of other animals to compete with the area's original inhabitants. The new immigrant is fast and outperforms its rivals in hunting; the winter nights grow colder, requiring thicker fur for protection and more nourishing food to maintain body heat. Our supposedly "perfect" animal is no longer in harmony with its environment; it is at risk of dying from cold or starvation.

However, the animal's traits vary in its offspring. Some of these offspring are faster than others—they still manage to catch enough food. Some are hardier and have thicker fur—they manage to stay warm enough during the cold nights. The slow, the weak, and those with thin coats soon die off. This same process happens repeatedly in each following generation. Through this natural process—which is so inevitable that it is impossible to imagine it not working—those best adapted to survive do so, while those least adapted die. It is sometimes said that we have no direct evidence of this selective power acting in nature. However, it seems to me that we have better evidence than even direct observation would provide because it is more universal: original: "viz." (videlicet) namely, the evidence of necessity. It must be so; for since all wild animals in—