44 STUDIES IN COMPARATIVE ANATOMY. 



C, and L. — 282, upper figure (L^), the origin is incorrect in the 

 lower figure ; 287-8 (Li). 



Spinalis dor si and rrvidtifidus spince form a continuous muscle, 

 lying internal to longissimus. The fibres take origin in the first 

 place from the sacrum and adjacent parts of the ilium, from the 

 under surface of the strong aponeurosis, which extends between 

 longissimus dorsi and the spinous processes, and also from the 

 vertebrse themselves along the line of the articular processes. 

 The muscle is inserted by fleshy fibres into the sides of the spines 

 of the vertebrse, as far forward as the fourth dorsal. The slips 

 corresponding to the fourth, fifth, sixth, and seventh dorsal spines 

 are tendinous, and form a strong bundle which passes more or 

 less completely into the ligamentum nuchae, and into a loop of 

 elastic tissue, which extends between the spines of the second 

 and fourth dorsal vertebrae. The muscle ends in a tendon which 

 arches over the spines of two vertebrse, and is inserted into the 

 side of the spine of the first dorsal. 



C. and L.— 282, figs. 1 and 2 (A) ; 295 (A). 



Complexus. — Beneath splenius a thin layer of yellow elastic 

 tissue is found to enclose a subjacent muscle, and to extend 

 forwards and outwards from the ligamentum nuchse to the 

 occiput. The muscle thus enclosed is complexus. It arises from 

 the articular processes of the four hindermost cervical, and about 

 twelve foremost dorsal vertebrse, slightly also from the ligamen- 

 tum nuchse in the anterior cervical region. It overlies the 

 funicular portion of the ligamentum nuchse, and is inserted into 

 the inner half of the superior curved line beneath splenius. 



C. and L.— 282, figs 1 and 2 (L) ; 287-8 (L) ; 295 (L). 



Ligamentum nuchm. — -This powerful elastic ligament springs 

 mainly from the spines of the three foremost dorsal vertebrae, 

 which rise successively higher in the order of their numbers. 

 The ligament is also strengthened by the bundle derived from 

 spinalis dorsi. Behind the third dorsal vertebrae it passes into 

 the interspinous ligament. At the level of the first dorsal 

 vertebra the ligamentum nuchas consists of two very distinct 

 masses, one superficial and the other deep, while a less con- 

 spicuous median partition may be observed. The upper or funi- 

 cular portion is free from bony attachment between the spine of 

 the seventh cervical vertebra and the occiput. At its insertion 



