THE SUBOCCIPITAL MUSCLES 401 



spinous processes of the contiguous vertebrae, one on either side of the interspinal 

 ligament. In the cervical region they are most distinct, and consist of six pairs, 

 the first being situated between the axis and third vertebra, and the last between 

 the seventh cervical and the first thoracic. They are small narrow bundles, 

 attached, above and below, to the apices of the spinous processes. In the thoracic 

 region, they are found between the. first and second vertebrae, and sometimes be- 

 tween the second and third, and between the eleventh and twelfth. In the lumbar 

 region there are four pairs in the intervals between the five lumbar vertebra?. 

 There is also occasionally one between the last thoracic and first lumbar, and one 

 between the fifth lumbar and the sacrum. 



The Extensor coccygis is a slender muscular fasciculus, which is not always present; it extends 

 over the lower part of the posterior surface of the sacrum and coccyx. It arises by tendinous 

 fibers from the last segment of the sacrum, or first piece of the coccyx, and passes downward to 

 be inserted into the lower part of the coccyx. It is a rudiment of the Extensor muscle of the 

 caudal vertebrae of the lower animals. 



The Intertransversarii (Intertransversales) are small muscles placed between 

 the transverse processes of the vertebra?. In the cervical region they are best 

 developed, consisting of rounded muscular and tendinous fasciculi, and are placed 

 in pairs, passing between the anterior and the posterior tubercles respectively of 

 the transverse processes of two contiguous vertebrae, and separated from one 

 another by an anterior primary division of the cervical nerve, which lies in the 

 groove between them. The muscles connecting the anterior tubercles are termed 

 the Intertransversarii anteriores; those between the posterior tubercles, the Inter- 

 transversarii posteriores; both sets are supplied by the anterior divisions of the 

 spinal nerves (Lickley 1 ). There are seven pairs of these muscles, the first pair 

 being between the atlas and axis, and the last pair between the seventh cervical 

 and first thoracic vertebrae. In the thoracic region they are present between the 

 transverse processes of the lower three thoracic vertebrae, and between the trans- 

 verse processes of the last thoracic and the first lumbar. In the lumbar region 

 they are arranged in pairs, on either side of the vertebral column, one set occupy- 

 ing the entire interspace between the transverse processes of the lumbar vertebras, 

 the Intertransversarii laterales; the other set, Intertransversarii mediales, passing 

 from the accessory process of one vertebra to the mammillary of the vertebra below. 

 The Intertransversarii laterales are supplied by the anterior divisions, and the 

 Intertransversarii mediales by the posterior divisions of the spinal nerves (Lichley, 

 op. tit.}. 



H. THE SUBOCCIPITAL MUSCLES (Fig. 389). 

 The suboccipital group comprises: 



Rectus capitis posterior major. Obliquus capitis inferior. 



Rectus capitis posterior minor. Obliquus capitis superior. 



The Rectus capitis posterior major (Rectus capitis posticus major) arises by a 

 pointed tendon from the spinous process of the axis, and, becoming broader as 

 it ascends, is inserted into the lateral part of the inferior nuchal line of the occipital 

 bone and the surface of the bone immediately below the line. As the muscles of 

 the two sides pass upward and lateralward, they leave between them a triangular 

 space, in which the Recti capitis posteriores minores are seen. 



The Rectus capitis posterior minor (Rectus capitis posticus minor} arises by a 

 narrow pointed tendon from the tubercle on the posterior arch of the atlas, and, 

 widening as it ascends, is inserted into the medial part of the inferior nuchal line 

 of the occipital bone and the surface between it and the foramen magnum. 



'- Journal of Anatomy and Physiology, 1904, vol. xxxix. 

 26 



