132 ROSS G. HARRISON 
June 19. Function of operated limb very much better, almost, if 
not quite, normal. Specimen preserved. No difference in size of 
limbs. 
D. Transplantation of half-buds 
18. Homopleural, dorsodorsal 
Experiment H. E. 6. April 12, 1917. Anterior half of limb bud to 
anterior half, normal orientation (fig. 120, 1). Operation on right side. 
Pronephros removed and transplanted. 
April 13. Perfectly healed. 
April 17. Limb bud on operated side normal. 
April 20. Same. 
April 30. Same. 
19. Homopleural, dorsoventral 
Experimental H. E. 31. April 9, 1918. Posterior half of right limb 
(inverted) in place of anterior right (fig. 120, 6). 
April 10. Wound perfectly healed. 
April 15. Operated limb bud smaller than normal, and stands out 
more sharply from l^ody. It is more distinctly marked off (points) 
anteriorly. 
April 18. Operated bud distinctly more massive (fig. 121, TR). 
April 21. Hand double, but coalesced to end. Digitations indis- 
tinct. 
April 30. Practically a normal right limb with an accessory hand 
growing from back of hand. The preserved specimen shows this to 
be a case of reduplication mirrored from a dorsal plane slightly inclined 
to the radial. The reduplicating member consists of second and third 
digits, {2' and 3') the former slightly liifurcated. The first (radial) 
digit is not doubled (fig. 122). 
Experiment H. E. 29. April 9, 1918. Ventral half (inverted) of 
right limb bud in place of dorsal right (fig. 120, 8). Embryo from 
which graft was taken, stained in Nile-blue sulphate. 
April 10. Healing good. Small round area still uncovered ])y 
ectoderm at ventroposterior border of wound. 
April 15. Operated bud has grown considerably, pointing dorsally, 
and slightly anteriorly. Whole free portion of bud covered by stained 
(grafted) ectoderm. 
April 18. Limb on operated side points dorsoposteriorly with redu- 
plicating nodule on posterior border. 
April 21. Limb short; doul^le hand. 
April 26. Well-developed double hand. Anterior memljer further 
developed, sticks out to side; is a left; palm anterior; other a right; 
dorsoradial reduplication. 
May 4. Almost perfectly symmetrical double hand. 
May 6. Specimen preserved. Arm as a whole a right, as is the 
posterior hand. This has three digits and a nodule for fourth, the first 
