1915] 



MERRILL ELECTROLYTIC DETERMINATION OF EXOSMOSIS 



553 



reading was higher at the end of four days than in the other 

 cultures (2-5) of that group, and continued higher through- 

 out, this fact loses its significance, as far as comparative ef- 

 fects are concerned, when the curve resulting from a 4-hour 





40 



Q 



/- 



3 



0) 



a 

 o 



8 



3 



es 

 > 



35 



30 



25 



20 



15 



10 



5 



III i I Mil i ™ " ™ 1 J 1 ' I 1 i 1 1 I I 1 



-III t 1 1 ft ™ri-f" 



— L- -J— I I x^ 3 ' - *± 



' I **r* *" ** t 



L 1 T . f J * ^ ft Jf 



, l" T III til * ■* "" * *l rC 



1 1 1 L *■*■"' ^ i z 1 [ 



^r i **x* t I > n r~ 



""^ ^^^^~^ — — ■ ■ ' — ' ■ r ^™*"^r — ™" ' ■^■■* — ^^~ ^^^ "^J *^™^^^™ — ^ ^"^^ — — ~^^ m ^^^ m ^™* ^^* - ^^^^^r"^^ ^^^ "^" — ^™* ■ ■■ ™ fc ■ ■ ^^™ ^' ' ■■ "^^^*M^^^ ^^^^r 1 ^* - ^^^^^^^^ ^^™ 



I 1 1 I I/ 1 I I ^i -L- ""x 



1 I f 1 l^^"* ,prf 



i ! m t i. -* j&% 



1 f / t t ^ "k T- *i 1 r- *" "" ^ 



III / t I £ * **^ i 1 [ -^i I X- "" ■* \ |T Jl* 



J\ 111 x ' ^r^i I J-"t "l 1 11 <Til 



ji\ r i i "# i *" HlZ rp^ 4t dpt 1 1 lL-» *■ ^x' \ \ 



TKo 11 ^ t ^c"~\ i 1 1 /T l *^* ■*" *i I I 



-tf^r -7 gT-Tl.i'f-T-r-T 



~T/ ~T *L i jt\ -^" - 1? J ^ , ! 1 I 



11 "T \ \ f\\\ ^C a \ \ I 





wT 1 FvL vi I <ffl _i^1 ^ I I 1 III 



;/ [y ** *I/VL f\ iyr\ [>% I X-* / T 1 1 | f 



W£ I ^ T t Tprt [ '^* — iH I ^fl r\\ *** jT I 1 T 



^^L^m^m^^^m ^^B ^^fc^^fca — ^K — -■- ^- — » ^fc» ^fc ^» » A - - A a 1 —*-^^^^^m^^^* ^ff^L-^*^^k^^t^^-^^^^^_^^^A^^^tl_ . ^^___ ^_^ ^ . A . 





^ j ^^^^ ^^fc ■ ^H^^^^^^^ 1 1 1 M ^^F m^^^^ 1 



F«_ f SjTT^i*!^^ 1 1 



?/ 1 "l^T* "* ( "t" 



r I I t 1 1 









iiliilliiiij 1 I | ^1 I II _l 



2 



4 



6 



8 



10 



Days 



12 



14 



16 



18 



20 



Fig. 15. Conductivity curves of cultures (series 10) in distilled 

 water subsequent to treatment, as follows: No. 1, N/20 MgCl 2 , 30 

 minutes; No. 2, N/20 CaCl 2 , 30 minutes; No. 3, N/20 MgCl 2 plus 

 N/20 CaCl 2 , 30 minutes; No. 4, control — placed directly into distilled 

 water; No. 5, N/20 MgClo, 4 hours. The cultures were 17 days old 

 at the time of treatment. The first reading was taken in all cases after 

 the roots had been in the distilled water exactly 30 minutes. 



treatment with MgCk is considered, and should no doubt be 

 interpreted as an individual variation irrespective of treat- 

 ment. In the case of No. 6, however, the curve for which rep- 

 resents the results of a 17-hour treatment with N/20 MgCl2, 

 we no doubt have a real effect clearly distinguished from the 

 controls. 



At the end of 20 days in distilled water following the treat- 

 ment the tops of Nos. 1-10 were all in about the same con- 

 dition, those of the treated plants showing no injury. Like- 

 wise the roots of Nos. 1-5 and 8-10 were practically normal, 

 with no, or only very slight, flaccidity ; those of No. 6, however, 

 were brownish in color and somewhat flaccid, while those of 



