we take against such evasive foes—working as we do in the dark—by using antiseptics, are evidently insufficient. A substance that kills one bacterium may not hinder the development of its neighbor, and our employment of antiseptics is always dependent upon their specific action. There exists no universal remedy against microbes. Science alone can teach us how to contend against them.—Translated for the Popular Science Monthly from the Revue Scientifique.
| HOW MUCH ANIMALS KNOW. |
By F. A. FERNALD.
NO phenomena in nature are watched with more interest by all classes, young and old, ignorant and educated, than the displays of intelligence in the inferior animals. From the dog, which occupies a position of intelligent companionship with man, down through the less favored species even to the lowest groups of animal life, we see manifested all degrees of that wonderful attribute which in its highest perfection constitutes the human mind. It is not surprising that these various indications of something like a capacity for thought should be of universal interest, but it also has a deeper meaning, which it is the office of science and philosophy to explore, and which relates to the profound and mysterious problem of "mind in nature." Before philosophy can make much headway with this question, however, there must be a more critical scrutiny of the question as to what degrees of intelligence different grades of animals really possess. Dr. George J. Romanes, in his recent interesting book on "Animal Intelligence," engages with this subject as a scientific question of comparative psychology, and he has done a good deal toward winnowing away the fictions that have become current in relation to the mental manifestations of the lower tribes, and has given us probably the most trustworthy book extant upon the subject. We cull from his pages a series of representative instances of animal sagacity which the reader will find both entertaining and instructive.
It is common to quote the oyster as the lowest example of stupidity, or absence of anything mental, and, as it is a headless creature, the accusation might not seem wholly unfounded. Yet the oyster is not such a fool but that it can learn by experience, for Dicquemase asserts that, if it be taken from a depth never uncovered by the sea, it opens its shell, loses the water within, and perishes. But oysters taken from the same depth, if kept in reservoirs where they are occasionally left uncovered for a short time, learn to keep their shells closed, and then live for a much longer time when taken out of the water.
This fact is also stated by Bingley, and is now turned to practical
