94 



After a detiiiled exainiiintioii of the speeiiiK'iis collfcti'd by myself I fciiud 

 thai every locality has a variety peculiar to itself. The niiinlier of localities lias 

 been trebled by the explorations of (jilbert and Evermann, and the number of 

 specimens laised from 250 to 825, and their detailed examination of these speci- 

 mens bears out the above statement for every locality examined by them. Un- 

 fortunately they allowed themselves to be side-tracked by minor issues, and did 

 not incntiiui this fact of local variation except in connection witli another s])ecies. 



1 collected at three localities in the Fraser basin. At Mission, B. C, I ob- 

 tained seventy-nine speciinens in water which is aflTected by the high tides. At 

 Sicinnous, at an elevation of 1,300 feet, I collected fifty-eight specimens. In Grifiin 

 Lake, at an elevation of 1,900 feet, I secured fourteen specimens. Four others 

 weri' secured at Kamloops, but these are too few to aid us in our study. 



The variation for tliese localities is represented by the three curves of figure 

 two. Tlie vertical lines stand for fin rays to total height of the figure for 100%. 

 The various heights of these curves represent the per cent, of specimens having 

 the given nund)er of rays. The variation is seen to be much the greatest at Mis- 

 sion, a fact which is largely to be attributed to the greater number of specimens 

 secured at this ))lace. The variation from the normal, which is nineteen rays, to 

 a higher number of rays, is as great as the entire variiition for the next locality. 

 At Sicamous a much larger per cent, has the normal numbir of rays, but tiie 

 normal number has l)een decreased to seventeen The curve for ( irifiin T.,ake is 

 interesting, l)ecause the normal number of niys lias again lieen decreased by two. 

 In other words, tlie higher tiu' altitude the fewer tiie number of rays and the nar- 

 rower the limit < f variation. ■ Moreover, the curves are not symmetrical for any 

 of the three localities, but in the aggregate the more gradual sioi)e is on the side 

 of an increase in the number of rays, a condition which, considering the general 

 variation of rays on tlie Pacific Slope, seems to indicate that the number of rays 

 of this species in the Frazer system is increasing, and that tlie increase is pro- 

 gressing from lower to higher altitudes. 



A glance at the remaining curves will be sullicient to show that no twociirvo 

 are alike, that the jier cent, of s{)ecinieus having a given number of rays dificrs 

 with each locality. Naturally the curves constructed fnun a hii-ge number of 

 specimens represent the true eoiiditions better thnii the ciiiN-es ediist meted from 



'■In their recent paper Gilbert and Evcnnann have niised this specific statement, wliich 

 occur.s in my paper quoted above, into the dignity of a "theory" anil "generalization.'" 

 which it was never intended to be, and their iirg'uments flgaini^t it as a " theory " and " gen- 

 eralization " arc, tlierefore, not aiipropriato. 



