262 THE POPULAR SCIENCE MONTHLY. 



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 experi- 

 ments bearing upon the conditions under which they are pro- 

 duced, 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 suj)- 

 pose that a horse could count uj^ 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 civili- 

 zation and commercial exchanges, which have, in nearly all cases, 

 caused the notion of numbers to be substituted for that of meas- 

 ure. — Translated for the Popular Science Monthly from the Revue 

 Scientifique. 



SKETCH OF F. A. VULPIAN. 



THE 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. 



Edme Felix Alfred Vulpian was born January 5, 1826, 

 and died in Paris, May 18, 1887. He was the son of a distin- 

 guished 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 sys- 



