SHORTER ARTICLES AND DISCUSSION 



ON THE RESISTANCE OF FUNDULUS TO CONCEN- 

 TRATED SEA WATERS 



T. TiJLUi: is ;i! PxTiPih!,! -1 Kiiii.liihis. .Icscribed by Giinthor 

 (79) undei- the iiainc /•'. Ix mi mhi , which is very closely related 

 to F. hrifrocllhi.-^, if not s|)('cifically identical with it." 



The coiiniion ha])itat of this K.m. lulus is alon- the shores ol 

 mau-rove swamps, in water normally having a saliTiity of -So-iiG 

 per mille (CI- 20 ± per mille ; sp. -r. about l.O^LV)-"^*. 

 When this Fundulns was placed in soa water which was allowed 

 to evaporate at laboratory temperature (about 27°) a good 

 number of specimens were found to resist a concentration of 

 about ^r sea water (C\ - 67 per mille). According to Loeb 

 ( F. lufn-orliti,^ at AVoods Hole may be brought to live 

 in a coiiccutratioii o(|uivalent to i% M or i% M, if the water be 

 slowly rvajioratcd. but a '-'s M concentration is rapidly fatal. 

 Soa uat. r a' Wno-K Hole i^ at about M/2 (salinity = 32 per 

 mill.' ^ Willi a ffccziug-point depression of 1.81° (Scott, '18), 

 whft'cas the l>.'tiiiii(la sea water is nearly %q M, with (accord- 

 ing to KnudsiMi s Table. 5) a freezing-point depression of 1,95.° 

 McClciiilnii ( 'll - touud the A of Tortugas water (S = 36 per 



Is 111 ■ rniio,i,.,-al.h' difference noted in the resistance of Fun- 

 diiliis talo'ti iVdiii thfse differing environments to be regarded 

 as an instance of adaptation brought about in nature? 



11. Tests were made at different seasons to discover the upper 

 limit of concentration which the Bermuda fundulns will toler- 

 ate. One of these experiments may be cited as an example: 



threo^sln-> ;Hin.iiia khimi ^ '2 hhi. nf m'.-i ^^■Mrr\ C] —-W.Goy^^; 



S = 35.50V,J hrnndU iVnui \hv unuv'royr cvck in win.-li the fundulus 



ture (2S°). In .•tMiia.-nim No. 1. lu.. lidics wc'iv still alive on Sept. 7, 



