[Hands and feet of prosimians primates. Attempts of morphologic characterization]

The length of the carpus and tarsus, the metacarpus and metatarsus, the fingers and toes of 142 prosimian apes was measured. The relationship expressed as a percentage was drawn up for each individual between the length of each osseous part and that of its third metacarpal in order to eliminate the differences related to the size of the rest of the body. This ratio was compared with that of man. The characteristic variations appeared at the level of the subfamilies. CONCERNING THE HAND: The carpus presented the same values as that of man except for that of the indris, which was shorter. The thumb had proportionally the same length as that of man, sometimes longer and sometimes smaller as in the Eulemurs, Hapalidea, Megalapidea, Indrises, Daubentonia and Perodictus. The different metacarpals, including the fourth, were a little shorter than the third. In these subfamilies, the second ray was also often shorter and even much shorter in the Megalapidea and the Perodictus. The other rays were a little longer, in particular the fourth which could exceed the third in rather many subfamilies. CONCERNING THE FOOT: The length of the tarsus was extremely variable. It was twice larger in the Galagoidae, definitely larger in the tarsius and discreetly in the Hapalidae, a little smaller in the other Lemurs and much smaller in the other Prosimian apes, joining in that the near totality of the simians. The hallux was proportionally as long as that of man and sometimes even longer. The metatarsals were sometimes a little longer, sometimes less long, but always appreciably of the same length between them. The other toes were short at the aye aye (daubentonia), of which the foot appeared even smaller than that of man. The toes of the other prosimious resembled much to the fingers and in the propithecus and the perodictus, the fourth took gigantic proportions. There has been establishment of an anatomical relation and functional calculus between the length of the last three rays of the hands and the feet of prosimian apes and the biomechanics of their trapezometacarpal and their first cuneometacarpal joints.