DR. GUNTHER ON THE ANATOMY OE HATTERIA. 
617 
of its fibres arises from a strong ligament extended between tuber ischii and the root of 
the tail ( d ) ; its tendon is inserted into the inner side of the end of the tibia. 
A very peculiar muscle (a) takes its origin from the eight or nine first inferior spinous 
processes of the caudal vertebral column and the lower surface of the corresponding 
vertebrae ; it is very strong, imbedded between the caudal muscles proper *, compressed, 
with the lower margin rounded, and separated from the surrounding muscles by very 
loose cellular tissue. It tapers behind into a point ; and becoming gradually stronger 
towards the trunk, it passes below and crosses the ligament extending from the tuber 
ischii to the root of the tail ( d ) ; the greater part of its fibres are here collected into a 
broad and strong tendon, which is attached to the inner trochanter-like protuberance of 
the femur ; but another portion (a 1 ), strengthened by additional fascicles from the broad 
ligament mentioned, passes into a slender chord-like tendon (a") which runs along the 
entire length of the femur, and is inserted into the end of the fibula. This muscle 
draws the limb backwards and rolls it outwards ; and with its slender tendon it assists 
in bending the lower legf. 
A very long and slender muscle ( h ) accompanies the ischiatic nerve ; it arises from 
the os sacrum, passes along the outer side of the femur, and is inserted into the outer 
side of the fibula; it bends the lower leg (M. agitator caudoe of Dr. Haughton). 
A very short muscle, entirely hidden by the two muscles last described, reaches from 
the tuber ischii to that part of the femur where, in Mammalia, the trochanter major 
projects ; it is an abductor muscle, and rolls the leg slightly outwards (M. quadratus 
femoris). 
Finally, a broad muscle, arising from, and lying immediately on, the entire lower 
surface of the pelvis, is inserted into the prominent inner tuberosity of the head of the 
femur ; it is covered by the hinder part of the obliquus externus and by the foremost 
part of the large flexor muscle ; it is the principal adductor of the limb. 
Of the muscles of the lower leg, those on the anterior side are readily distinguished as 
tibialis anticus , extensor digitorum ( communis longus), and peroneus longus ; the ex- 
tensor terminates in two slender tendons only, inserted into the metatarsal bones of the 
second and third toes. 
The muscles on the hinder side of the lower leg are disposed in several layers. The 
* In a male Grammatophora it is situated above the penis and its muscle. 
t Dr. Haughton (l. c .) describes and figures this muscle in tbe Crocodile as M. extensor femoris caudulis, and 
expresses its use in the following words :■ — “ The Crocodile, resting on mud, progresses chiefly by using bis bind 
feet as paddles ; and in tbis use of tbem tbe great caudal extensor of tbe tbigh is the most powerful and im- 
portant muscle employed.” Tbe fact that tbis muscle is developed in ground- and tree-lizards as well as in the 
Crocodile, prevents us from adopting the idea of its being an organ specially adapted for tbe mode of life of the 
latter. When in the progress of ordinary locomotion one of tbe bind limbs is advanced, and its sole beeomes 
tbe fixed point, tbis muscle lifts the hind part of tbe body forwards, in which it is materially assisted by having 
a double insertion, viz. on tbe upper end of tbe upper leg, and by its slender tendon on tbe lower. When tbe 
trunk is fixed, this muscle simply draws backwards the limb, effecting at tbe same time a slight flexion of tbe 
lower leg. 
