MACALISTER—ON PRONATOR MUSCLES. yA bys 
of plane is less marked. Among the Carnivora, Insectivora, Cheirop- 
tera, and Rodentia, I have found it to be similar in origin in the seal, 
dog, dingo, wolf, fox, brown and Virginian bears, otter, lion, tiger, cat, 
hyena, paradoxure, weasel, marten, hedgehog, bats (both Vespertilio 
and Pteropus), rabbit, hare, rat; among Edentata, it is regular in the 
six-banded Armadillo, the three-toed sloth, the anteater and Orycte- 
ropus (Humphry); among Marsupials, it is likewise similar in Ma- 
eropus major and Vallabiense, Dasyurus, Phascolomys, Phalangista, and 
Virginian Opossum ; in Hchidna and Ornithorhynchus it is large, and 
seems to act as a powerful flexor. Among Pachyderms, it is present in 
rudiments in the elephant, hyrax, pig, and peccary, and among Rumi- 
nants, traces of it are present in the camel and dromedary, and, according 
to Meckel, in the roebuck. Itis absent in Cetacea, Solipeda, the rhino- 
ceros, sheep, goat, nylghaie, Tragulus napu, sambur, axis, and cariacus. 
Cuvier says, but incorrectly, that it is absent in bats. 
Among birds, it has often an accessory head from the medial lga- 
ment of the elbow joint, which remains separate for its entire extent 
from the condyloid head. This portion, however, is not homologous 
with the human coronoid head; for in the latter case the median nerve 
is between the two muscles, in the former the nerve is underneath both 
muscles. This double condition occurs in the golden eagle, the falcon, 
vulture, owl, stork, Weka rail, grebe, jabiru, and crane. I have not 
been able to trace this separation in the ostrich, rhea, emu, or casso- 
wary. In the penguin, according to Schoepss, this muscle is modified 
into two parallel tendinous bands (Schoepss quoted by Rudinger, ‘‘ Uber 
die Muskeln der Vordern Extremitatem der Reptilien und Vogeln,’’ 
Tigh. x., fig, 22, No. 9). 
Among reptiles, the origin of the round pronator is normal, and its 
presence is tolerably constant in those possessing limbs. It is present 
in the Chelonia imbricata, caretta, and mydas, Testudo europea, Emys 
geographica, Lacerta viridis, Chameleon, Iguana tuberculata (Mivart), 
crocodile, and alligator. In all these its origin is regular, its action is 
mainly that of a flexor, and it attains its reptilian maximum in the 
alligator. 
Among Amphibia it is tolerably constant, as in Reptilia, and it 
exists in Rana temporaria, mugiens, esculenta, in Bufo cinereus and 
vulgaris, in triton, the maculated salamander, siredon, proteus, and 
others. In many of these its origin is extensive, as in R. mugiens, and 
occupies the entire of the medial process of the lower end of the humerus. 
In these animals it is large, and acts as a flexor of the elbow, and as 
such was named by Hcker ‘“‘ flexor antibrachii medialis.”’ 
The insertion of this muscle is subject to little variation, being 
usually inserted into the radius for a variable extent ; its attachment 
is to a central part of the bone, about the middle-third in the Primates 
in general, as in most of the Quadrumana, and many of the Carnivora, 
and others. It is attached to the ulnar side of the middle-third of the 
radius in many of the Amphibia, which is contrary to its usual habit, 
and indicates its assumption of a flexor action. It stretches to the 
