. The Journal of experimental zoology. con-nection is made. This, then, would not only readily account TRANSPLANTATION OF LIMBS IN AMBLYSTOMA 129 for differences in the number of spinal segments which contrib-ute nerves to the limbs in different species, but it would alsoaccount for slight variations in the segmental contribution tothe limb plexus in a given species—a condition which, as hasbeen referred to above, has long since been observed. If the extent of the limb rudiment were the only factor toaccount for this latter phenomenon, then the limb rudiment, ifdisplaced the distance of severa
. The Journal of experimental zoology. con-nection is made. This, then, would not only readily account TRANSPLANTATION OF LIMBS IN AMBLYSTOMA 129 for differences in the number of spinal segments which contrib-ute nerves to the limbs in different species, but it would alsoaccount for slight variations in the segmental contribution tothe limb plexus in a given species—a condition which, as hasbeen referred to above, has long since been observed. If the extent of the limb rudiment were the only factor toaccount for this latter phenomenon, then the limb rudiment, ifdisplaced the distance of several segments, should so effect thenerve contribution that the new plexus would come from seg-ments corresponding to the position occupied by the displacedlimb rudiment. The results of the experiments reported in thispaper indicate that, in addition to the position and extent of thelimb rudiment, still other factors govern the innervation oflimbs when developed from rudiments lying beyond the con-fines of the orthotopic position. .MY3. Fig. 3 Camera-lucida drawing of an embryo of Amblystoma in the tail-budstage. The circle situated ventral to the pronephros (pn) indicates the positionof the limb rudiment. X 15. EXPERIMENTAL The experiments were carried out upon embryos in the tail-bud stage (fig. 3). The extent of the limb rudiment at thisperiod has been described above. The technique employed inembryonic limb transplantation is so well known through thepapers of Harrison, Braus, and others that no special descriptionis here required. All of the experiments were made upon theanterior limb rudiment. The majority consisted of transplant-ing the right anterior limb rudiment to an abnormal (hetero-topic) position on the same side of the body from which it was 130 S. R. DETWILER taken, and at distances ranging from one to seven segmentsposterior to the normal situation. These experiments consti-tute the autoplastic transplantations. In other experiments the normal anterior limb was l
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1920
