166 



Appendices to Fourth Annvxtl RepoH 



Belgium (Van Beneden) ; Denmark (Meinert) ; Norway, from Chris- 

 tian ia to the Lofoten Islands (G. 0. Sars) ; Mediterranean, at Goletta, 

 Messina, and Syracuse (G. 0. Sars). 



I can myself testify to the following localities : — Whitby, Yorkshire, 

 and Seaton Carew, County Durham (A. M. N.); Sunderland (G. S. Brady) ; 

 Cumbrae, Firth of Clyde (D. Bobertson) ; Tarbert, Boch Fyne (Fishery 

 Board Laboratory) ; Naples (Zool. Stat.). 



It is a shallow- water form, found on a sandy bottom, usually in 0-10 

 fathoms. Now first recorded as British. 



APPENDIX F.— No. IX. 



On bed and pale MUSCLES in FISHES. By William Stirling, 

 M.D., Sc.D., Brackenbury Professor of Physiology and Histology in 

 Owens College, and Victoria L'niversity, Manchester, formerly Pro- 

 fessor of the Institutes of Medicine (Physiology) in the University 

 of Aberdeen. AVith 3 Plates (IIL, IV-jV.) 



For a long time anatomists and physiologists have been acquainted with 

 the fact that the muscles of different animals differ notably in colour, 

 structure, and physiological properties, and that even in the same animal 

 there are differences in the colour amongst the muscles. Every one is 

 familiar with the fact that the muscles of the breast of a fowl are lighter 

 in colour than those of the legs ; and even after being cooked this dilfer- 

 ence is quite marked. The muscles of the breast in some birds also differ 

 in colour; thus in the partridge the pectoralis major is dark coloured, 

 while the minor is much lighter in tint. Similar differences obtain in the 

 rabbit, as was shown by W. Krause* in 1868. Thus the semitendinosus 

 is a red muscle, while the vastus intemus and adductor magnus are pale 

 muscles. That the colour of the red muscles is not due to the blood 

 present in their blood vessels was proved by Kiihne,t who washed 

 out the blood by means of a half per cent, solution of common salt, and 

 found that the muscles still retained their colour — that, in fact, it was 

 incorporated with the sarcous substance, and was identical with hsemo- 

 globin, giving a spectrum the same as that of the blood pigment. Ean\'ier]: 

 observed that the red and pale muscles of the rabbit differed not only in 

 colour but also in histological and physiological properties. Structurally 

 the fibres of the red muscles, as compared with the pale, are smaller in 

 diameter, while the round muscle-corpuscles or nuclei are numerous, and 

 placed peripherally under the sarcolemma ; in the pale muscles, however, 

 they are fusiform, fewer, and scattered throughout the sarcous substance. 

 In the pale muscles the transverse striation is less regular than in the red. 

 They also dilfer in the arrangement of their blood-vessels. In the pale 

 muscles the arrangement of the muscular capillaries is such as obtains 

 in ordinary striated voluntary muscles. In the red muscles, however, 

 the capillaries between the muscular fibres are more wavy, while the 

 transverse connecting capillaries and the veins frequently have small oval 

 or fusiform dilatations on them like little aneurisms. Physiological they 

 differ also. Banvier showed that the pale muscles were not so easily 

 tetanised as the red ones ; but he estimated the number of shocks neces- 



* Die Aiiatomie d. Kaninchem. 1868. 



t Ueber d. Parbstoff d. Muskeln. Virch. Arch. 1865, 



t Archivu Physiol. Aon/i., &.c. 1874, p. 5. 



