404 THE ZOOLOGIST. 



and this is likely to yield substantial data to clear up several of 

 the knotty fish problems. Mcintosh kept a record for a year of 

 those pelagic fauna found in St. Andrew's Bay, and the monthly 

 variation is most interesting and instructive. He compares the 

 whole to a spindle, the thick mass corresponding to May-July, 

 therefrom tapering on either side to the ends=January. To 

 these surface forms, as a whole (plants and animals), Hensen has 

 applied the technical term "Plankton" (wXayKTos, wandering).* 

 He believes the economical food yield of the ocean can be statisti- 

 cally determined by quantity. Without here questioning his 

 theory, one doubted by Haeckel, it certainly is more obvious that 

 there is an intimate interdependent relation between marine life 

 and seasonal fish numbers. This through plants furnishing 

 pabulum to invertebrates, and these again to piscine groups. To 

 pursue the links in the chain further, the plant profusion is deter- 

 mined by meteorological conditions, and we have arrived at 

 physical causes more within our ken, and probable after results 

 determinable beforehand. Thus step by step are we likely to 

 arrive at reasons for the annual gluts or dearths of fish, early 

 or lateness of seasonal appearance, food migrations, &c. The 

 more pressing or immediate interests of fisheries' industries, 

 meanwhile, have not been lost sight of by the scientific inquirer. 

 Much has already been accomplished towards ascertaining the 

 limits of sexual maturity in both sexes, and the vexed questions 

 of trawling and temporary closure of areas have received due 

 attention. Into these I do not propose to enter other than by 

 pointing out the assumption (a fashion revelled in by the younger 

 biologists) that our fishing is producing a stunted race of flat- 

 fish (?). 



The institution of Sea-fish Hatcheries, so extolled in America, 

 is yet on its trial in this country. Opinions thereon are divided, 

 the balance being rather in favour of those who maintain the 

 Scotch verdict of "not proven." It is questionable whether 

 the working of a hatchery could be made profitable or not. The 

 weak point in the Dunbar hatchery is liberation only in the fry 

 stage. To remedy this defect, what in contradistinction may be 

 termed " nurseries " are suggested. In these, with larger enclosed 



* The German remarkable " Plankton " Atlantic Expeditions are object 

 lessons. 



