42(i SCHULTE, SEI WHALE. 



of the vertebrae well dorsad, towards but not actually from, the transverse processes. The bulk 

 of its fasciculi arise from the fifth, fourth and third dorsal vertebrae ventrally, those from the 

 sides of the bodies and from the second and first dorsals form but a small fraction of the belly. 

 This has nearly a sagittal course, but in the cervical region the muscles of the two sides diverge, 

 again converging towards the occipital so that an oval space is left between them in which appears 

 the deeper plane. As the belly ascends in the neck it receives laterally the scalene, and as it 

 passes the atlas it is joined by a short thick muscle from the transverse process (rectus capitis 

 anticus minor). These three elements are blended in a common belly which inserts into the 

 base of the cranium at the mesal margin of the auditory bulla as far rostrad as the alae of the 

 vomer. Here the fasciculi from the dorsal vertebrae extend farthest rostrad, the scalene are 

 laterad and for the most part at the caudal margin of the bulla, the rectus minor near the caudal 

 margin of the occipital. 



The deeper stratum is small and confined to the spine. Three portions can be distin- 

 guished, one longitudinal and two oblique. The longitudinal is best developed and extends along 

 the ventral common ligament of the vertebrae from the third dorsal to the ventral arch of the 

 atlas, arising from the more caudal and inserting into the more rostral vertebrae. The majority 

 of its fasciculi, however, reach the atlas. The caudal oblique portion, arising in common with 

 the longitudinal, is inserted into the transverse processes of the fifth and sixth cervical vertebrae. 

 The rostral oblique portion arises from the transverse processes of the fifth and fourth, and 

 inserts in common with the longitudinal portion into the atlas. Thus in the deep plane, which 

 is not described by Carte and MacAlister, we find a perfectly organized longus colli independent 

 of the superficial stratum, which for this reason seems better taken as the representative of the 

 rectus anticus major. 



The hypaxial muscle of the lumbar region and pedicle is an enormous mass occupying 

 the region between the transverse processes and the bodies of the vertebrae and extending from 

 the last caudal vertebra to the eleventh rib. Dorsad it is in relation in its whole length with 

 the transversarius. Mesad it is in contact with its fellow, the chevron bones being interposed 

 as far rostrad as the anus, beyond which the muscle twists somewhat on itself, so that its mesal 

 surface becomes meso-ventral. Against this surface rest the kidneys and ureters, and between 

 the muscles of the two sides are interposed the aorta and postcavse. Superficially in the abdomi- 

 nal region the muscle is covered by the transversalis, the obliqui and lumbar aponeurosis; in 

 the pedicle it is partially overlain and concealed by the ischio-caudalis and the aponeurosis of 

 the rectus. The lumbar and caudal nerves and blood vessels pass dorsal to it to the cleft between 

 it and the transversarius. 



In structure it resembles the longissimus dorsi, being divided caudally into two tracts which 

 become merged rostrad. Its lateral tract begins as a great tendon attached to the ventral 

 aspect of the caudal vertebrae, and receiving minor tendons laterad from the region of the rudi- 

 mentary transverse processes. From the beginning of the flukes rostrad to the level of the hypo- 

 gastric arteries, this great tendon resolves itself into a series of five smaller tendons of origin, 

 which add themselves to the mesal tract of the muscle. This tract begins at the junction of the 

 flukes and pedicle by fleshy fasciculi derived from the deep surface of the great tendon. Rostrad 

 it increases in size, deriving additional fasciculi from two sources, mesad from the chevron bones 

 and laterad from the tendon slips before mentioned. In the abdominal region it gains attach- 

 ments to the bodies of the vertebrae and the ventral surfaces of the transverse processes, extending 



