Nerve-Conduction in Cassiopea Xamachana. 



17 



the solubility of particles of barium sulphate is about inversely propor- 

 tional to the size of the particles; and as colloidal particles are more or 

 less soluble, one would expect their solubility to increase as the average 

 diameter of the particles decreased. 



• • ■ ■ • ■ • • ' • * • ' ' * ' ■ ^^ 



V\A\AAAAAAVVAAAAAAAAAAAAAAAAV*aaaaaaaaa-aaaaaa/^aa/^^ 



Sea, wa.teT i.?^ c. 



-*''•' ..................... If. ..■■;.■■■■..... 



■ ''*■'*■'■•■* . . ■ ■ ■ » 



+ 5 of >6-« Hj.0 



■ ■ 



• ■ • ■• ■ 



•JO" •• •• ' 3 OV 



|\jM/\/\/\A/W\A^ 



' ■ ■ ■ 



7 •••;/; 30 •;•■ ;• Si" 



/w\/\J\JV\imvw\i\A/\A^W\/\AiV\Al^w 



6 -V-O - • '• -^n 



50 



50 •• 



dO?7 



■A^fWWWM^MA/W^A^^MA^^^^A^^A^A^AMAA/^^ 



"Returned to %^^. watev 30% 



Fig. 12. — A ring of Cassiopea in dUuted sea-water, showing decline in rate of nerve-conduction 

 as dilution proceeds; also recovery of rate when the ring is replaced in natural sea- 

 water. 



lilt 



I fc I » » » 



> > ■ I I 



' • ■ * I I I 



' ' — t I — I — i — t- 



<j I ■» 



sea. vva.t 



e -r* 



25?^ C. 



>««»«'■'■' t I I I—I 1 1 1 1 1 « I I • 1 II 



Fig. 13. — Showing change in rate of nerve-conduction in subumbrella ring of Cassiopea in 

 NaCl+CaCU. In the lowest Une the movement of the ring has become very irregular, 

 indicating that it is about to stop. 



