of the, Fishery Board for Scotland, 



such an immature condition as to make it ail but certain that they could 

 not spawn for months, if not for a year. These small fish were caught 

 at the same time and place, and it seems extremely probable that they were 

 fish of the same age just as they were of the same size and appearance. It 

 seems to me, then, that the variable size both of the spawning herring as 

 well as of their ova probably has a considerable effect on the ultimate size 

 of their progeny, but we can scarcely institute a special case of variety on 

 these grounds alone, if the fish have every other characteristic in common 

 with the larger herring. 



Without a more critical examination than has yet been made, it would 

 be unwise to speak definitely on the question of variety among the herrings 

 of our coasts. The only evidence as yet found from the present investiga- 

 tion in favour of such a distinction between the summer and winter 

 herrings, consists in the more posterior position of the dorsal, pelvic, and 

 anal fins, the doubtfully smaller head, and the slightly lesser size of the 

 summer herrings. 



We have seen that the fishing in winter is generally prosecuted with a 

 larger meshed net than is in use in summer. Hence the rather smaller 

 size of the summer herring as we find it may be accounted for. But we 

 can scarcely so account for the difference in the other characters. If the 

 herrings caught in summer are smaller only on account of the smaller mesh 

 of the nets employed to take them, and we therefore conclude that there 

 are equally large fish in summer as in winter, and that these small fish are 

 merely younger members of the same race, we ought in such case 

 to expect them to have a relative length of head intermediate to 

 that possessed by the immature and large herrings, that is, a head 

 relatively longer than that of the larger winter fish ; but although the 

 difference is very little, such as it is, it is the other way. Again, 

 we have found that the summer herrings have the dorsal and anal fins 

 situated further back on the body than those of the winter. The 

 immature fish have these fins relatively far forward, so that if the 

 smaller ripe summer fish are simply young fish we would expect to find 

 their fins at least as far forward as the others. On the whole, the exami- 

 nation of these characteristics in our Scottish herrings, so far as this pre- 

 liminary and general investigation is to be depended on, seems to point to 

 the conclusion that a certain difference does exist between the majority of 

 the summer herring and those of the winter. There remains, however, 

 the disturbing fact that examples of all the extremes of all the variations 

 are represented among the herrings of both seasons. Of more importance 

 still is the fact that what may be called the commonest ground of variation 

 found in the winter herring is not only in proximity to, but overlaps 

 largely the commonest ground of variation among the summer fish. All 

 the variations, too, are found not only in fish frequenting the same place 

 and in the same season, but even in the same shoals, and it does not seem 

 possible to avoid the conclusion that there must be much interbreeding 

 between the possessors of these varying characteristics. Whether the 

 smaller ripe fish are fully grown or not, it is tolerably certain that many 

 varieties of all kinds must result from the interbreeding of these with 

 larger fish, and with all the intermediate forms ; and this is likely to be 

 more pronounced among filsh spawning en masse like the herring, and sub- 

 ject to the general conditions of fertilisation among fish, viz., that it is 

 external, and that the ova of one and the same herring are subject to and 

 according to observations, almost certain to be fertilised by several males. 



While suggesting, therefore, that there is a certain distinction between 

 our summer and winter herrings, I am indisposed to consider the matter 

 as conclusively proved without the facts being submitted to a more minute 



G 



