Published online by Cambridge University Press: 11 May 2009
The present investigation was undertaken at the invitation of H.M. Treasury, in consequence of an application to the government from H.M. Inspectors of Irish Fisheries for a scientific investigation into the life-history of the mackerel. The problem to the solution of which the inspectors attached particular importance was the relation to one another of the spring and autumn schools of mackerel which regularly visit the Irish coasts. In the spring a multitude of large fish approach the south and west coasts of Ireland to breed. In the autumn schools of immature, but usually well-grown, mackerel come around the island. According to one of the inspectors, the Rev. W. S. Green, there is a sharply defined interval between the two visitations of fish.
page 240 note * The irregularity in the number of fish in the samples from Ireland was due, I understand, to a curious system of depredation during transit which prevails in those parts, and is sanctioned by custom or, at least, endurance.
page 248 note * Two large mackerel, one of each sex, were forwarded to me by Mr. Green in February. They measured 16 ins. in length, and were caught off Gariness, Co. Cork, on Feb. 23rd, 1898.
page 257 note * It is curious to notice that the transverse bars of the adult mackerel occupy a positon in relation to the myotomes which is quite different from that occupied by the vertical lines of chromatophores in young mackerel from 14 to 18 mm. in length, according to Holt's description and figures (this Journal, V., 1898, p. 116, figures 3 and 4). In preserved specimens at this early stage Holt states that, “on the sides of the trunk, the chromatophores are set more thickly at the lines of division of the myomeres than elsewhere,” i.e., along, instead of between, the septa which scparate the myotomes.
page 265 note * The small Brandon sample, dated April 16th, has been combined with that dated April 22nd, in order to obtain a representative percentage for this locality.