PROGRESS IN BIOLOGICAL INQUIRIES 49 



closely the collection and publication of fishery statistics for the 

 varioiis countries interested in the <z;reat bank fisheries of the western 

 North Atlantic, and as a i)art of this prourani it was su<^gested and 

 agreed upon by both the Canadian and the United States representa- 

 tives that definite plans be laid for systematic fisli measuring, such 

 as has been conducted .by various European countries for a number 

 of years. This systematic sam[)lin<2; of the commercial catch has 

 proved to be of great value in the investigations of the fisheries of 

 the eastern Noi-th Atlantic and North Sea, and it is believed that 

 similar work on the American side of the Atlantic would prove 

 equally valuable. 



Other matters discussed were the need for investigation of the 

 mackerel and halibut fisheries and the collection of water tempera- 

 tures at various points along the entire Atlantic coast. 



iNTEinoij ^^'AT^:KS 



COUKdOMN/E Ol'' TUK OIIKAT LAKKS 



With regard to the investigation of the systematic relations and 

 ecology of the Avhiteiishes and related species of the (xi'eat Lakes 

 Basin that is being made by Dr. Walter Koelz and John Van Oosten, 

 the first draft of the account of all the species of Leucichthys and the 

 one species of Prosopium in that region was finished during the 

 latter lialf of 1921. There remain the consideration of coregonus 

 and the unifying of the various accounts before the manuscript 

 will be ready for publication. Valuable observations on the Core- 

 gonine fishes were made also in several inland lakes of Marquette 

 County, Mich. 



Studies were made of the life history of the Lake Huron white- 

 fish {Coregonnfi clupeaformis). as found at Alpena, Mich. Many 

 data were obtained fi-om the analysis of the scales, including rates 

 of growth, 'age composition of commercial catches, year of sexual 

 maturity, etc. 



The analyzed data of whitefish captured in July, 1923, revealed 

 some interesting facts hitherto unknoAvn. The samples indicate that 

 in summer 70 per cent of the commercial catches of whitefish at 

 Alpena consist principally of fisli in their fifth year. The youngest 

 fish taken were in their fourth year, the oldest in their eighth. 

 Those in their fourth year averaged 401 millimeters (15.8 inches) in 

 length and those in their eighth year 517 millimeters (20.4 inches), 

 the increase during each of the intervening years being about 1 

 inch in the length of eacli fish. The data also definitely indicate 

 that the opinion generally held by the hatchery employees and 

 others relative to the age 'at which' whitefish first become sexually 

 mature is erroneous. Whitefish reared under artificial conditions 

 may become sexually mature in 3 years but those grown in I^ake 

 Huron certainly do not. No sexually mature fish under five years of 

 age luis been taken by the investigators. Of the female whitefish 

 in their fifth year taken in 1923, 33 per cent were mature while 67 

 per cent w^ere still sexually immature. It is not until the sixth year 

 that the majority (74 i)er cent) become mature. 



Another result having important bearing on the ])roblem of con- 

 servation is that 55 per cent of the females of these summer samples 



