Scientific Investigations. 



The Investigation by Matthews. 



Matthews * tested the problem of the existence of races among 

 the Scottish herrings. 



He used a similar method to that adopted by Heincke, but he 

 made the comparison between the shoals by the aid of the observed 

 averages of the measurements. He examined 1100 herrings. 



The characters selected by Matthews were : — 



1. Length. The length was the distance from the tip of the lower 

 jaw, when the mouth was closed, to the point where the silvery sub- 

 epidermic layer covering the body terminates. The latter point was 

 called the base of the caudal fin. 



The fish was, on arrival, placed on a sheet of paper in such a 

 position that a straight line would run through the tip of the closed 

 lower jaw and the fork of the tail. A pencil was carried round the 

 fish, so that a rough but fairly accurate life-size sketch was formed 

 of it. The following points were then accurately marked of? : — 



2. Anterior end of the mandible. 



3. ,, ,, ,, pre maxilla. 

 Jr. Centre of the eye. 



5. Back of head, of supra-occipital bone, which has an almost 

 straight posterior border. This forms a much better standard of 

 length of the head than the length of the side of the head, which 

 includes the opercular bone— liable to considerable alteration in 

 position from various causes. 



6. Base of anterior ray of dorsal fin. 



7. Base of posterior ray of dorsal fin. 



8. Termination of the tail (as described above). 



9. Tip of the caudal fin. 



10. Base of the posterior ray of the anal fin. 



11. Base of the anterior ray of the anal fin. This point has 

 nearly alvv^ays the same relative position with regard to the anus, 

 any difference being more apparent than real, occurring especially 

 during the spawning season from the enlarged and tumid condition, 

 and from its contracted state in the spent condition. 



12. Base of the first ray of the pelvic fin. 



13. End of the branchiostegal membrane. 



14. Articulation of the lower jaw. 



15. Number of rays in the dorsal fin. 



16. ,, ,, ,, anal fin. 



17. ,, ,, ,, caudal fin. 



18. ,, ,, ,, pectoral fin, 



19. ,, ,, ,, pelvic fin. 



20. Number of keeled scales. 



The condition of the reproductive organs was noted. 

 The measurements were all reduced to ratios of the length of 

 the fish. 



The fishes were all perfectly fresh when measured. They had 



* Matthews, J. U., "Report as to Variety among the Herrings of the Scottish 

 Coasts." Pt. I. ith. Aimwil lieport of the Fishery Board for Scotl^nid lor 1885. (1886.) 

 P. 61. Pt. II. 5th Annual Report of the Fishery Board for Hcotlund for 1886. (1887.) 

 P. 295. 



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