THE ATLANTIC MONTHLY.
A MAGAZINE OF LITERATURE, ART, AND POLITICS.
VOL. IX.—JANUARY, 1862.—NO. LI.
[METHODS OF STUDY IN NATURAL HISTORY.]
I.
It is my intention, in this series of papers, to give the history of the progress in Natural History from the beginning,—to show how men first approached Nature,—how the facts of Natural History have been accumulated, and how those facts have been converted into science. In so doing, I shall present the methods employed in Natural History on a wider scale and with broader generalizations than if I limited myself to the study as it exists to-day. The history of humanity, in its efforts to understand the Creation, resembles the development of any individual mind engaged in the same direction. It has its infancy, with the first recognition of surrounding objects; and, indeed, the early observers seem to us like children in their first attempts to understand the world in which they live. But these efforts, that appear childish to us now, were the first steps in that field of knowledge which is so extensive that all our progress seems only to show us how much is left to do.
Aristotle is the representative of the learning of antiquity in Natural Science. The great mind of Greece in his day, and a leader in all the intellectual culture of his time, he was especially a naturalist, and his work on Natural History is a record not only of his own investigations, but of all preceding study in this department. It is evident that even then much had been done, and, in allusion to certain peculiarities of the human frame, which he does not describe in full, he refers his readers to familiar works, saying, that illustrations in point may be found in anatomical text-books.11. See Aristotle's Zoölogy, Book I., Chapter xiv.
Strange that in Aristotle’s day, two thousand years ago, such books should have been in general use, and that in our time we are still in want of elementary text-books of Natural History, having special reference to the animals of our own country, and adapted to the use of schools. One fact in Aristotle’s “History of Animals” is very striking, and makes it difficult for us to understand much of its contents. It never occurs to him that a time may come when the Greek language—the language of all culture and science in his time—would not be the language of all cultivated men. He took, therefore, little pains to characterize the animals he alludes to, otherwise than by their current names; and of his descriptions of their habits and peculiarities, much is lost upon us from their local character and expression. There is also a total absence of systematic form, of any classification or framework to express the divisions of the animal kingdom into larger or lesser groups. His only divisions are genera and species: classes, orders, and families, as we understand them now, are quite foreign to the Greek conception of the animal kingdom. Fishes and birds, for instance, they considered as genera, and their different representatives as species. They grouped together quadrupeds also in contradistinction to animals with legs and wings, and they distinguished those that bring forth living young from those that lay eggs. But though a system of Nature was not familiar even to their great philosopher, and Aristotle had not arrived at the idea of a classification on general principles, he yet stimulated a search into the closer affinities among animals by the differences he pointed out. He divided the animal kingdom into two groups, which he called Enaima and Anaima, or animals with blood and animals without blood. We must remember, however, that by the word blood he designated only the red fluid circulating in the higher animals; whereas a fluid akin to blood exists in all animals, variously colored in some, but colorless in a large number of others.