374 Journal of Coiiiparativc Neurology and Psychology. 



2. With the fovea! ami parac t'lUral rt-^ions (|iiamitativc cxperi- 

 ments could iu)t \ cry well be inaclc bcraiise the i:rcrn and hiiic lights 

 mixed with the white of the itlei) retinal lii:ht more ea>il\ than did the 

 red liiiht. Nevertheless, a marked increase in the sensitivity was 

 tound. I. i;. w. 



Nagel, W. A. f".inii,'f r.iiil>;uhtiiiiL;(ii iihri ^Vw Wiikmii; <lt> I >uu kt- iiiul ilt-s 

 galvaiii>clii-n Stioiiu-^ aut da^ dunklfadaptiirli' Aii^r. (/.uiii Icil iku li 

 VerMulu'ii vi.ui Ihnn. laiul. iiud. liii-cKWi' :\ N ) . Zii/. /. /'vr. u. /'/ns. 

 d. Smncsori^ane, Hd. 34, pp. JS5-J91, l<)04. 



This contributor first confirms the results of (J. !•] Mci.ikk, wlio 

 has reported, in effect, that the sensitivity of tiic eyes for inadcipiate 

 stimulation by the Ljalvanic current is independent of the state of ada|)- 

 tation of the eyes. The author's next obser\ations com em the differ- 

 ences in the behavior of the pressure phosphenes when the eve is 

 adapted for light and when adapted tor darkness. It was tound. that 

 with a given position of the eye, and with a definite pressure uii the 

 eyeball, the same form ^\{ pressure phosplu-ne < nuld be re< ailed again 

 and again. Having chosen, witii e\e adapted for light, a definite 

 phosphene as a standard (in this c-ase a bright ring with one or two 

 concentric rings inside of it) Professor N.xgki. made some c ()mpari^ons 

 when the eye was adapted to darkness. The result was that the in 

 tensity of the pressure |)husphene in the eve adapted to darkness was 

 slightly increased. (Qualitatively the ai>pearance of the two phosphenes 

 was very different. The ring in the eye adapted to the light wa^ yel 

 lowish and small; in the eye ada|)ted to the dark it wa^ bluish white 

 and noticeably broadened. 



Since the author is (li( hromatic (a greenish lone in \cllow and 

 a violet t<tne in blue could not be perc eived), it oc( urred to him that 

 the color of the phosphene seen in the eve adaptetl to the dark might be 

 complimentary to the color of the phosphene seen in the eve a(la|tted to 

 the light. S(j he repeated the abcne experiment upon persons |hisscs.< 

 ing normal color \ision. They stated that the phosphene seen in the 

 eye adapted to the light appcarc-d yellowish, iiu lining to red : the 

 phosphene seen in the e\e a(la[)ted to the dark a|>peare(l bluish or 

 bluish-white. 



The author next tested the gal\ani< |iho^phenes in the eve adapted 

 to the light and in the eye adapted to the darkness, to see if any differ 

 ence in color could be found. The phosi)lienes prodm ed in this way 

 were always (juaiititatively and (pialitativcK alike in the tw.i e\es. 



Numerous experiments were then made to test wlicthcr the sensi 

 tivity of the eyes adapted to the darkness, is altered by the effect ot an 



