MYOLOGY OF REPTILES. 215 



are red, like those of the warm-blooded classes. The want of 

 colour relates to the comparatively small proportion of red blood 

 circulated through the muscular system, 1 and the smaller propor- 

 tion of red-particles in the blood of fishes : the exceptions cited 

 seem to depend on increased circulation with great energy of 

 action ; and, in the Bonito and Tunny, with a greater quantity of 

 blood and a higher temperature 2 than in other fishes. The deep 

 orange colour of the flesh of the Salmon and Char depends on a 

 peculiar oil diffused through the cellular sheaths of the fibres. 

 The muscular fasciculi of Fishes are usually short and simple : 

 and very rarely converge to be inserted by tendinous chords. 3 The 

 proportion of myonine is greater in Fishes than in other Verte- 

 brata ; the irritability of its fibres is considerable, and is long re- 

 tained. Fishermen take advantage of this property, and induce 

 rigid muscular contraction, long after the usual signs of life have 

 disappeared, by transverse cuts and immersion of the muscles in 

 cold water : this operation, by which the firmness and specific 

 gravity of the muscular tissue are increased, is called ' crimping.' 



§ 47. Myology of Reptiles. — The myonine of the air-breathing 

 Hgematocrya is always pale in colour, and the fibres are tenacious 

 of their irritability : the energy of the muscular contraction is in 

 some instances, and on some occasions, great ; but cannot be ex- 

 cited in frequent succession, such power being soon exhausted. 



In the ichthyomorphous Batrachia the recent myonine presents 

 a pearly clearness, as in some fishes, and the chief bulk of the 

 tissue is arranged in transverse segments, of which, however, the 

 progress of massing into longitudinal groups is greater than in the 

 Sharks. In the Salamander, figs. 140, 141, the neural or upper 

 halves of the myocommas, separated at the midline of the back by 

 a furrow lodging cutaneous follicles, have a tendency to group 

 themselves into distinct longitudinal tracts, as they advance for- 

 ward : just as their homologue — the common ' erector spinas ' in 

 man — subdivides into the longitudinal masses called ' sacro-lum- 

 balis,' ' longissimus dorsi,' and 'spinalis dorsi,' &c, in its corres- 

 ponding course. The median portion, fig. 140,5 a, in Salamandra, 

 representing the spinalis dorsi in the trunk, has its anterior 

 insertions in the neural arches and spines of the cervical and occi- 

 pital vertebra? ; and there answers to the ' spinalis ' and ' semispi- 

 nal ' colli, and to the ' biventer cervicis ' and ' complexus.' The 

 lateral portion, answering to the longissimus dorsi and sacro-lum- 

 balis in the trunk, represents, by its insertions, the ' transversalis 

 colli ' and trachelo-mastoideus, fig. 140, 5, in the neck. The haemal 



1 xlviii. pp. 4, 16. - h. 3 XLix. p. 3. 



