198 Dr. A. D. Waller. On the [Oct. 23, 



Later and with altered position of lens on electrodes. 



1000+ a response of - trace. 

 1000- „ -0-0004 volt. 



5000+ „ -0-0005 „ 



5000- „ -0-0010 „ 



Exp. 8. Dogfish. — Isolated lens. 



1000+ gives -0-0012 volt, 

 1000- „ -0-0020 „ 



The response is abolished by pressure. 



Exp. 9. Cuckoo Fish (white). — Some hours (1 4 or 5) after death. 

 The eyeball gives no response to light or to electrical excitation. 



Its lens, to 5000 + gives - • 0020 volt. 



5000 „ -0-0050 „ 



Set up in connection with three electrodes so as to be excited 

 through AB, and led off through AC or BC (as for the entire eyeball). 

 The lens responses are as follows : — 



B C A 



AB Exc. 5000 - < 



AC Besp. - -0035 — — 



AB Exc. 5000+ - 



AC Besp. - -0025 < 



AB Exc. 5000 - - 



BC Besp. - -0015 ^ 



AB Exc. 5000+ ► 



BC Besp. - -0006 



Exp. 10. Cuckoo Fish (yellow). — Isolated lens. A few hours (1 4 or 5) 

 after death. 



Exc. 1000 + gives - • 0030 volt. 

 1000+ „ -0-0050 „ 



On returning to London, I first tried salmon's eyes, and then 

 adopted the cod's eye as affording a constant supply of suitable 

 material. 



Exp. 11. Salmon (from a London shop). — Isolated lens. No response. 

 The fish had been kept in ice. 



1000+ gives nil. 



1000- • „ „ 

 10000+ „ 

 10000- „ „ 



