[The herring fishery is carried on at Plymouth during the winter months, when the adult herring seek the inshore waters for spawning. Besides these, however, the so-called “harbour herring” are taken in the summer and autumn; these appear to be the produce of the last spawning season, i.e. six months to a year old. Mr. Cunningham has shown me specimens taken in the Cattewater in May, 1889, which vary from 3½ to 5 inches in length. Those which are at present being brought to the Laboratory (September, 1890) are 9 or 10 inches in length, but their reproductive organs are still at an extremely early stage of development. Further observations on these harbour herring are much needed, and are being gradually made.