940 THE OSTEOLOGY AND MYOLOGY OF THE DEATH ADDER, 



The Dorsal Muscles. 



The dorsal muscles may be divided into two groups, the mesio- 

 dorsal and the latero-dorsal. The first consists of the spinalis and 

 longissimus sets, the second of the sacro-lumbalis and accessorius. 

 Mesio-dorsal group (Humphry), Neuro-mesial (Owen). 



The superficial fascia that covers the dorsal muscles is scanty. 

 It is connected above with the neural spines, and from thence 

 runs outwards over the spinalis, longissimus, and sacro-lumbalis, 

 where it blends with the superficial layer of the external oblique. 



The fascia is the representative of the external oblique stratum 

 continued over the dorsal muscle. This is well shown in the 

 anterior fourth of the body of Dahoia, where the muscular fibres 

 of the oblique layer completely replace the fascia. In the other 

 forms examined it was only on approaching the head that the 

 muscular fibres became conspicuous. 



M. SPINALIS DORSI. 



M. capito-vertebralis, Hoffmann ; Der aiifsteigende Muskel 

 zwiscUer cUn Dorn- und Gelenk/ortsdtzen, D'Alton ; 3£. spinalis, 

 Hiibner, Owen, Jones ; Dorn- und Halbdornniuskel, Meckel. 



The spinalis dorsi arises from the upper portion of the lateral 

 surface of the neural spine, and from an aponeurosis which 

 stretches between the neural spines and the zygapophysis, covering 

 in the multifidus. Each part of the muscle runs forward as a 

 rounded belly, ending in a long slender tendon which is inserted 

 into the apex of the neural spine of the ninth vertebra from the 

 origin. The tendons of the muscles are arranged so that the 

 anterior ones lie external to, and beneath, the posterior ; at the 

 same time the tendons are connected with one another by fascia 

 so that an aponeurosis is formed. The fascia is also modified to 

 form a number of thecal sheaths, thus enabling the tendons to 

 move with great facility. Tendons from the longissimus joiu this 

 aponeurosis. 



The muscle presents no points of difference in any of the forms 

 examined, and the above description might apply even to the 



