[Observations, analyses and experiments on the use of the hand in Callithrix jacchus Erxleben, 1777. Part II. Fine analysis of prehensive behavior].

The use of the hand of the common marmoset (Callithrix jacchus Erxleben, 1777) was analysed on the basis of observations and experiments conducted on 56 animals of all age. During arboreal locomotion Callithrix jacchus makes use of the hands for support and for grasping to maintain its balance, The palmar region serves as the main means of support, while the findgers in the locomotor grip also contribute to maintaining balance and support. The greater the need for maintaining balance, for example, during vertikal climbing or in movement along the narow branches, the mre complete the djustment of the hand form on the surface and the more complete the alignment of the hand on the branch will be. Additional support is supplied by the longitudinal palm furrow, caused by the radio-ulnar adduction of the hand edges and by the clinging properties of the volar pads...