132 
ZOOLOGY: A. S. GILSON, JR. 
Proc. N. a. S 
TABLE A. 
Distance from outer boundary of pigmented epithelium to external 
limiting membrane 100 
Extent of retinal pigment processes in : 
Normal Light Fish 82 2 
Normal Dark Fish 59 =•= 3 
Light Fish, 0.2 cc. Adrenalin 1 : 1,000 intra-abdominally 80 =±= 1 
Dark Fish, 0 .2 cc. Physiological salt solution, intra-abdominally 64 =t 1 
Dark Fish, 0.2 cc. Adrenalin 1 : 1,000 intra-abdominally 77 =t 2 
Dark Fish, 0.2 cc. Adrenalin 1 : 10,000 intra-abdominally 66 =±= 3 
Dark Fish, 0.2 cc. Adrenalin 1 : 1,000 intra-muscularly 74 11 
Dark Fish, 0.2 cc. Adrenalin 1 : 10,000 intra-muscularly 68 =i= 3 
Average weight of fish =4.3 grams 
where d is the deviation of any observation from the mean and n is the num- 
ber of experiments in the series. 
processes having an average extension of 77. Qualitative examination of 
these retinas showed a marked tendency toward the Ught condition. In 
these animals, however, the secondary, distal concentration of pigment was 
usually lacking. Injection into the abdominal cavity of weaker adrenalin 
solution, and injection into the dorsal musculature gave generally unsatis- 
factory results. Dark animals into whose body cavity physiological 
salt solution had been injected showed a barely significant change in the 
condition of the retinal pigment. Whether this very slight change is due to 
the effect of the physiological salt solution itself, or to the secretion of 
adrenalin by the animal remains to be determined. In all cases, the 
scale melanophores of animals injected with adrenalin showed the extreme 
proximal migration of the melanophore granules which has been described 
by previous workers. 
Klett ('08), working with the frog, and using only light animals, was 
able to discover no effect upon the retinal pigment when a solution of 
adrenalin was injected into the blood stream. Injection of a very strong 
solution of adrenalin into the anterior chamber of the eye, however, caused 
a contraction of these melanophores. Bigney believes, and probably 
rightly, that this effeci: was due to the toxic nature of the solution used. 
Fujita ('11) used dark frogs and found that the injection of adrenalin 
into the bloodstream caused a distal migration of the retinal pigment. 
This finding was confirmed by Bigney. 
Experiments upon Fundulus, here reported, demonstrate that the in- 
jection of adrenalin will cause a distal migration of the pigment processes 
in the retinas of dark animals, but produces no significant change in the 
already extended processes of light animals. The changes are of a reverse 
nature in the scale melanophores, the injection of adrenalin into the animal 
