SEVENTEENTH REPORT. 



NOTE OX THE rROPORTIONS OF THE SPIXES IN 

 THE WHITEFISH. 



BY RAYMOND PEARL.^ 



Ill tlie siiniiiier of 1!M)1. while eiigajied in a study of variation in 

 certain tisli. iu connection with the I>iol(»<j,ical Survey of the (ireat 

 Lakes directed by Professor Jacob Keighard, I collected some 

 statistics regarding the proportions of the sexes in the common 

 Whitefish of Lake Erie, Core<jonus albiis Jordan and Everman. In 

 more recent years interest in problems connected with the de- 

 termination of sex has impressed me with the great dearth of 

 definite statistics regarding the normal sex-ratios of even the com- 

 monest animals. For that reason it seems now desirable, merely as 

 a matter of definite record in the literature, to publish the data for 

 Coregoniis. 



The fish were taken in deep water gill-nets in Lake Erie off 

 Dunkirk, X. Y. The data were obtained by standing beside the 

 benches where the fish were dressed and recording the sex of each 

 as it was opened. There was no selection whatever in the recording. 

 The results represent the sex distribution of that sample of the 

 Whitefish population in the early summer which was caught in a 

 gill-net. 



The statistics follow : 



Date Male Female 



July 1, llJOl .14 15 



• 2 112 120 



-3 98 129 



-5 43 52 



" G 119 139 



Total 380 455 



This gives a sex ratio of 848 males : 1,000 females. 

 Maine Agricultural Exi»erinuMit Station. 

 Orono, Me. 



1. The writer is indebted to Mr. W. C. Kendall of tlie Uiiieau of Fisheries, for a 

 discussion, /;i lit., of the ti'rniinolo{;y of the wliitelisli of the (ireat Lalves. 



