MYOLOGY OF KEPTILES. 215 



ure red, like tliose of tlie wnmi-ljloodcd classes. The want of 

 colour relates to the comparatively small proj)ortioii of red 1)lood 

 circulated through the muscular sj-stcm,' and the smaller propor- 

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

 seem to de])end on increased circulation with great energy of 

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

 Mood and a higher temperature- than in other fishes. The deep 

 orange colour of tlie fiesh of the Salmon and Char depends on a 

 ])ecidiar oil diffused thi'ough 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.'^ The 

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

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

 tained. Fishermen take ad^•antage of this property, and induce 

 rigid muscidar contraction, long after the usual signs of life haAO 

 disappeared, by transverse cuts ajid 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. JSIyology of Rtqit'des. — The my(jniiie of the air-breathing 

 lliematocrya is always pale in colour, and the fibres arc tenacious 

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

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

 cited in frequent succession, such power being soon exhausted. 



In the ichtliyomorphous Batrachia the recent myonine pi-esents 

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

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

 jirogress of massing into longitudinal groups is greater than in the 

 Sharks. In the Salamander, figs. 140, 141, the neural or U})per 

 halves of the myocommas, separated at the midlijie of the l^ack by 

 a furrow lodging cutaneous follicles, have a tendency to group 

 themselves into distinct longitudinal tracts, as they advance for- 

 ^s'ard : just as their liomologue — the common ' erector spina) ' in 

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

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

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

 i-epresenting the spinalis dorsi in the trimk, has its anterior 

 insertions in the neural arclics and spines of the cervical and occi~ 

 ])ital vertebras; and there answers to the ' spinaHs ' and ' seniisj)!- 

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

 lateral portion, answering to the longissinuis dorsi and sacro-lniii- 

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

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



' XLvni. lip. 4, IG. ^ L. ' XLix. p. 3. 



