THE 



AMERICAN NATURALIST 



Vol. XLI June, 1907 No. 48G 



A GRAnilC MF/rilOl) OF ( ()iniHLA'riX(J FISH 

 EXVIKONMFN r AN D I )IS'rin HI ''ll< )\ 



albi:rt hazfx wrigiit 



It is some years since ornitli()lof?ists saw the advantages of a 

 graphic means of rej)resentiiig com])lex bird waves and their 

 coincident relation to i)liysical conditions. In ichtliyologv a 

 schematic method whereby fish (hstribution and cnxironnient 

 can be correlated is not less valuable. 



The study of a stream and its fishes inv()lv(-s the consideration 



ma.ss of data, that one is mijH'ilc.l ro a(i(.|)t scuu" uraphic method 

 to make results appear (|nickl\- and clcarK. 



stic.un indiKlnii, i \ i-utx ..t'[H-^'''l» ...ndition. I lu fiLi < on- 



th. mouth ot th( Muaui. and the (oiu.pondinil N»ni<al on the 

 right of the chart is its source. The dotted verticals numbered 

 below (1-S) mark mile points. Beneath the "Misc. Data" space, 

 these mile lines are not dotted but continuous. 



The hea\7' horizontal oj)posite eacli species indicates the ranjxe 

 of that species in the stream. \\ hcivvcr the hori/oiital is broken, 

 it indicates the occasional oeciirrence ot die species. ANheiiever 

 a species gains entrance to a --ti'eam troiii two or mon> pomt> an 

 arrow tip at the end of each ot its raiiuv hues iii.licate- the (hrectioii 

 ot Its migration; e. 7., in our hvpotheiie -iivani the carp. ( i/pnniis 



T\w continuous horizontal above tin- fiiNi specie, in the li.t. 

 upu.entsth( .intake ot tlu uatu 1 lu boitom i. .ho^n bx ,!„ 

 (UiMd hue labele.1 "Bottom (.t Mm am llu asna^t dtptli 

 351 



