102 
THOMPSON YATES LABORATORIES REPORT 
and hand, the above case indicates that the field of the internal saplienous is larger in the foot 
of thj Monkey than in that of Man. Section of the musculo-cutaneous and anterior tibial 
nerves leaves the whole of the thumb, tlie plantar face, the sides, the nails, and chief part of the 
dorsal aspect of the end phalanx of each of 2nd, 3rd, 4th, and 5th digits, and the outer third as 
well of the dorsum of the 5th digit, still sensitive. Section of the external plantar being then 
performed, adds to the existing area of anaestliesia (i) the contiguous sides of the 4th and 5th 
digits, (2) the corresponding lateral halves of their plantar aspects, (3) and of their terminal 
phalanges, dorsally as well, together with (4) an oblong strip of the outer part of tlie sole extend- 
Patch of anesthesia 
after cutting exter- 
nal plantar nerve. 
Contribution from 
external saphenous 
to external plantar. 
Internal saphenous. 
Patch of anses- 
thesia after sec- 
tion of internal 
plantar nerve. 
Strip along which 
internal and ex- 
ternal plantars 
overlap. 
ing half-way to the heel. If, instead of section of the external plantar, the section be of the 
internal plantar, then the additional area of anaesthesia includes (i) the tip and all but a small 
dorsal strip of tlie rest of the hallux, (2) the tips, sides, and plantar surfaces of the 2nd and 3rd 
digits, (3) the tibial side of the whole length of the 4th digit, and (4) a triangular patch of the 
planta, including almost all the hairless part of the thenar eminence and inwards up to the middle 
line of the planta, except that the outer edge of the patch is, in its more proximal part, directed 
towards the median line of the 3rd digit, and only over the distal end of the 3rd metatarsal bone 
curves outwards to the outer side of the cleft between 3rd and 4th toes, to run along the plantar 
aspect of the 4th, distinctly on the tibial side of the middle line of that digit. 
