of the Fishery Board for Scotland. 



171 



Fig. 4. — Similar Section, showing relation of coloured muscle to the lateral 

 line. 



Fig. 5. — Tail of a herring showing red muscles. 

 Fig. 6. — Tail of a haddock showing red muscles. 



Fig. 7. — Eed muscular fibre of a whiting, showing the fatty granules in the 



sarcous substance. 

 Fig. 8. — Transverse section of red muscular fibres with fatty granules. 

 Figs. 9 & 10. — Transverse section of the body of a mackerel. 

 Fig. 11. — Transverse section of the body of a whiting. Low-power view. 



F., subcutaneous fascia ; K., red muscles ; P,, pale muscles ; S., 



septa ; V.C., vertebral column. 



APPENDIX F.— No. X. 



ON THE BLOOD OF NEPHROPS NOEWEGICUS. J3y W. D. 

 Halliburton, M.D. (Lend.), B.Sc, M.R.C.P., Sharpey Physiological 

 Scholar, and Fellow of University College, London. 



The nephrops norwegicus is one of the commoner decapod crustaceans ; 

 it is often called the sea-crayfish ; and it belongs to the same family of 

 Decapoda, the Astacidse, as do the common fresh-water crayfish {Astacus 

 jiuviatiUs) and the lobster (Homarus vulgaris). 



Large quantities of this animal vvere sent to me from Scotland by 

 Professor Cossar Ewart for the purpose of determining the properties of 

 their blood or hsomolymph. A certain proportion of the animals died in 

 transit, but a sufficient number remained alive for the purposes of the 

 investigation. 



I have to thank Professor Schafer for much help and valuable sugges- 

 tions during the progress of the investigation. 



The blood of the nephrops may be stated in general terms to have 

 similar properties to those of other decapods, but it exhibits certain 

 differences of degree, though not of kind, which will be dwelt upon 

 presently. 



It will be convenient to divide the account of the examination of this 

 blood into the following parts : — 

 Part I. The Blood as a Whole. 



Part II. The Phenomena of Spontaneous Coagulation. 

 Part III. The Proteids of the Plasma and Serum. 

 Part IV. The Colouring Matters of the Blood. 

 General Conclusions. 



Part I. — The Blood as a Whole. 



The blood is obtained by making acts in the ventral region in the 

 soft integuments between the abdominal segments, or in the claw. In 

 this way, from a large nephrops, some twenty or thirty cubic centimetres 

 of blood can be readily obtained. 



Colour. — When first shed the blood is nearly colourless. It has an 

 opalescent or milky appearance from the presence of numerous amoeboid 

 corpuscles in it. This appearance is, however, but momentary, for 

 coagulation begins to occur almost instantaneously. The blood, after 

 being a few minutes in contact with the oxygen of the atmosphere, 

 acquires an indigo- blue tinge. This colour, which is seen with great 



