284 THE MYOLOGY OF THE RAVEN. 



I have any knowledge of, and is scarcely excelled by 

 the so-called, and famons " fifth layer " that adorns the 

 dorsal region of Homo. 



Owen fonud the ohliquus colli fully developed in 

 the Ajyferi/x, and says of it that " this series of muscles 

 seems to represent the transversalis colli, wdiicli is 

 the anterior continuation of the longissimus dorsi 

 in Mammalia, but it differs in being inserted into the 

 oblique, instead of the transverse processes. In the 

 direction of their filjres these fasciculi resemljle the 

 semis'pinalis colli, l:)ut they are inserted into the 

 oblique processes instead of the spines of the vertebrae " 

 (Anat. of Verts., vol. ii. p. 86). It will be noticed that 

 we found in the middle of the series in our j^resent 

 sul)ject that they do pass to the neural spines.^ 



1 In his dissections of the Ajjteryx, Professor Owen also made out 

 in the dorsal region of the back the spinalis dorsi, the multijidus 

 S2n7ice, and the ohliquo-spinales. These muscles in the Raven cannot 

 be satisfactorily differentiated — if indeed they are present at all — or 

 even their barest rudiments. Upon a number of specimens I have 

 taken great pains to endeavour to isolate them, but was after all 

 forced to the conclusion that they do not exist in so high a type as 

 Corvus. I quote in full here from the second volume of the Ana'omy 

 of Vertebrates what Professor Owen says of them as they occur in 

 the Apteryx, so we may have the data for comparison. According 

 to this authority, the spdnalis dorsi is brought into view by the 

 removal of the dorsal portion of the longus colli ^^osticus and the 

 longissimus dorsi. 



" It arises by two long, narrow, flattened tendons from the 

 spines of the eighth and seventh dorsal vertebrse : these pass 

 obliquely downward and forward, expanding as they proceed, 

 and terminate in two fasciculi of muscular fibres : the posterior 

 bundle passes forward beneath the anterior one, and inclining 

 inward and upward, divides into two portions, inserted by long- 

 tendons into the spines of the second and first dorsal vertebraj ; it 

 then sends a few fibres forward to join the outer and anterior 

 fasciculus, which is partly inserted by a slender tendon into the 



