Papers from the Marine Biological Laboratory at Tortugas. 39 



Sea. water 2.I' 



7S- Sea.v/ate>- + 25 deyttrose 2.VS C 



50 sea wc-v-tev ^- 50 cle^tvos 



2%°C 



iiO sea. -water + 50 dextvose, 



Sea.wa.tev 2'6!'^C 



Fig. 4. 



29'"C. 



A \'\ ^. ^..^s^l 



50 clistiLled >/w£Lt ev -^ bo seav. ^^.\e.^ 



Z^j^ C 



sea wate-r Z^? 1 C 



33. 3i cle>ttrose -\- fefc.Gt. sea vA(d.ter 



3 I." 15 C 



^^ 



A. 



i.s cl IS "I (.Lied -^ 75 sea vvaiev 





sea. Nwaiev 



T u Uj fe , ^ ti 5 6 n.. T w. 2 g! 7 5 C. 



MVJ\JVJVJVJVJVJVJV_,\_JVJVJVJVJVJVJVJ^ 



sect wairev J^l^j ■=? , 6^. ii^^. Aw^ 27.' I C. 



Fig. 5. 



Table 5 shows the relative rates of pulsation of 2 medusae and of nerve- 

 conduction in 20 rings of subumbrella tissue of Cassiopea in sea-water, and 

 in sea-water mixed with 0.9 molecular dextrose. 



Table 6^ shows the relative rates of nerve-conduction in subumbrella 

 tissue of Cassiopea xamachana in sea-water diluted with distilled water, and 

 also in sea-water diluted with 0.9 molecular dextrose. (See tables 4 and 5.) 

 The practical coincidence of these two curves indicates that the changes 

 in rate of nerve-conduction are due to corresponding changes in the con- 

 centration of the electrolytes and not to changes in osmotic pressure. 



1 See fig. 6, which shows that these two curves are apparently identical, the differences between them 

 being probably due to errors of experimental nature and individual variation. 



