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 again, after every trip, at the head of the train, in readiness for the next trip; but at the end of the thirtieth trip they turn their heads in the opposite direction, or toward the stable.

Facts of this kind ought to be tested by most precise experiments bearing upon the conditions under which they are produced, and upon different subjects. Are not the horses warned of the end of their stint by some exterior sign, such as a change of conductors, the departure of a squad of workmen, or the arrival of the horses that are to take their places, or by the meal-hour? Is not the conclusion that they count the number of their trips arrived at too quickly?

It would predicate a very high degree of development to suppose that a horse could count up to thirty in any given number of hours. A man in such case would nearly always make mistakes, unless he had some means of registering the trips as they were completed.

It is nevertheless established that some birds and quadrupeds are capable of counting up to four or five, and perhaps more. It can not be disputed that the higher limit of this faculty may vary according to species, and also to individual traits, since the mathematical faculties of men are very great in their variations. But we have reasons for believing that the geometrical faculty in animals supersedes the arithmetical faculty, and that the latter has been developed in man under the influences of industrial civilization and commercial exchanges, which have, in nearly all cases, caused the notion of numbers to be substituted for that of measure.—Translated for the Popular Science Monthly from the Revue Scientifique.



HE name of Vulpian is associated in some way or another with most of the important physiological discoveries of the age. It is, according to Dr. Charles Richet, because, whenever a new experiment was published, he took it up at once, tested it, and perfected it, toning down with his critical and judicial spirit the exaggerations and rectifying the errors in the accounts, and, making the general application of the newly gained fact, gave it the right to be quoted as good physiology. Thus he cast light on all the problems which he grappled with.

was born January 5, 1826, and died in Paris, May 18, 1887. He was the son of a distinguished French lawyer, and was graduated in medicine in 1854. He was soon afterward appointed to the Museum of Natural History, where he conducted a series of investigations on the nervous 