dAAADfAX FiSHERIEf; EXPEDITIO\, U)1',-1o 161 



From the figures here shown, it would certainly seem very likely that the method 

 in question might serve to define the differences between the herring from different 

 parts of the Canadian waters. Thus the sample from Newfoundland, for instance, 

 differs distinctly from the Magdalen islands and Northumberland strait samples as 

 regards the number of rays in the dorsal fin, which character likewise seems to indicate 

 a difference between the herring of the Magdalen Islands and Northumberland strait 

 on the one hand, and those of the Atlantic coast on the other. This character also, 

 therefore, might possibly prove of importance if the error of the averages were 

 reduced by increasing the number of specimens in the samples. Somewhat the same 

 applies, indeed, to the number of vertebrae; the present samples are too limited to 

 reveal any absolutely indubitable difference in this character. 



On comparing the figures for the sample from Northumberland strait with those 

 of the one from Magdalen islands, no essential difference is apparent, and one is 

 reminded of the great resemblance in point of growth exhibited by the samples from 

 these waters, with the good 1903 year-class common to both. It would be interesting 

 to investigate the localities in question more closely, with the aid of more extensive 

 material, in order to determine, if possible, whether the differences in growth and in 

 age-composition found, warrant our considering the herring of these two waters as 

 separate groups. 



The sample from West Ardoise differs strongly from that taken at Lockeport, by 

 the smaller number of rays in the dorsal and anal fins. The differences are so great 

 that it seems almost certain they cannot be accidental. Here again is a ixtint which 

 might well be investigated further with a larger amount of material. Possibly the 

 results might then lead to a definite distinction between several forms of herring 

 along the Atlantic coast, based on the study of morphological characters and growth 

 measurements. In our present investigations, the paucity of materiaf rendered it 

 impossible, as already mentioned to demonstrate with certainty the existence of 

 any difference in point of growth between the herring of Lockeport and those of West 

 Ardoise. In further investigations it would also be well to include samples from the 

 north side of Cape Breton island, in order to determine the character of these fish 

 more accurately than it has here been possible to do ; the same applies to the waters 

 between Port Hood, Souris, and cape George, as well as the more southerly parts of 

 the Atlantic waters of Canada. 



One special subject for growth investigations which, owing to the favourable 

 conditions in these waters, have every chance of success, is the distribution of the her- 

 ring in the gulf of St. Lawrence, studied by means of quite small samjjles of old fish, 

 examined as to growth. The very remarkable difference in growth between the her- 

 ring from the southern portions of the gulf, and those from th3 coast of Newfoundland 

 renders it, as far as I can see, an easy task to determine, even with small samples, 

 whether the fish in question can be said to belong to one or the other growth type. 

 Such identifications of the herring could be carried out in a manner similar to the 

 method of Heincke for the identification of herring by means of morphological char- 

 acters. Heincke's method may be briefly described as follows : It is desired to ascer- 

 tain whether a given specimen, of which certain characters have been determined by 

 count and measurement, more resembles in such respects the one or the other of two 

 races in which these same characters are known (average and variation). The first 

 step is to ascertain in what degree the six^cimen differs, as regards each separate char- 

 acter, from the average values for same in the one race, the difference in each case 

 being expressed in units of the respective standard deviations. The differences thus 

 obtained are then squared and added together. Similarly, the deviations of the speci- 

 men from the average of the other race is then determined, the differences here being 

 expressed in units of the respective standard deviations for the race in question. 

 The specimen then differs in the lessor degree — i.e., resembles more — the race for 

 which the resulting sum of the squares of the differences is the less. Table 4S shows 



