250 MESSRS, MIVART AND MURIE ON THE [Feb. 28, 
whatever of any division of the tendon of this muscle, @ fortiori not 
of its muscular part. 
The extensor longus digitorum is a very slender muscle, the 
smallest of the leg-extensors and flexors of the lower limb ; yet it has . 
a double origin, as also in Cheiromys'. The smaller head arises by 
a thin muscular bundle from the outer side of the tuberosity of the 
~ tibia, with also a small pencil of fibres coming from the inner side of 
the head of the fibula; the larger origin consists of a rhomboidal, 
flat, muscular fasciculus attached to the inner side of the middle third 
of the fibula. The muscle gives a tendon which splits into four sub- 
divisions, sending one to each of the four outer digits, that to the 
index being the smallest. 
The extensor longus hallucis is of about equal magnitude with 
the preceding, but quite distinct from it. It arises from more than 
the upper half of the external margin of the tibia. Its tendon is in- 
serted into the proximal end of the last phalanx of the hallux (fig. 6, 
E. 1. h). 
In Loris, according to Meckel’, this muscle seems to be con- 
founded with the extensor longus digitorum. 
The peroneus longus is remarkable for its great extent, covering 
about one-half of the anterior surface of the leg ; but there is nothing 
unusual in its origin or insertion (fig. 6, P. 7). 
The *peroneus quinti digiti is very distinctly developed, the 
muscular fibre being of considerable length. It arises between the 
peroneus longus and peroneus brevis, completely hidden by them, 
and is inserted by an extremely delicate tendon into the proximal 
end of the second phalanx of the fifth digit (fig. 6, P.g.d). This 
muscle, we believe, was first described under the above name by 
Professor Huxley*, in his Hunterian Lectures for 1864; but it has 
been noticed by Meckel* among the extensors of the digits. 
Burdach® has also described it under the name peroneus tertius ; 
and W. S. Church® likewise refers to it under the same designation. 
But this muscle can scarcely be the homologue of the peroneus ter- 
tius of Man, inasmuch as it arises not on the tibial side of the pero. 
neus brevis, but on the fibular side. Moreover Professor Huxley 
remarks, it is sometimes represented in Man by a slip from the ten- 
don of the peroneus brevis. 
The gastrocnemius.—It is difficult to understand how Professors 
S. Van der Kolk and W. Vrolik can have asserted that ‘‘ Jes jumeaua 
et le muscle soléare sont trés-forts,” unless they have mistaken one 
head of the flexor longus digitorum for part of the gastrocnemius. 
It is the more probable that they have done so, as they have de- 
scribed the semimembranosus as “‘embrassant les jumeaux,’ whereas 
it is the flexor communis longus which this muscle directly embraces. 
So far from being “ trés-fort,’’ the gastrocnemius is exceedingly 
1 Owen, /. c. p. 68, pl. 25. figs. 1, 3. no. 35. 
2 Anat. Comp. vol. vi. p. 499. 
3 Med. Times and Gaz., 9th July, 1864, p. 40. 
+ Anat. Comp. vol. vi. pp. 438 and 440. 5 Loe. cit. pp. 46-55. 
© Nat. Hist. Review, Jan. 1862, p. 92. 
