DAY: PIGMENT-MIGRATION IN EYE OF CRAYFISH. o2¢ 
TABLE III. 
Intensity varied. Time constant (10 minutes). Evaluations made from 
the same observation-records as in Table II, but with reference to three graded 
migrations exhibited by animal 28. 
Red. | Blue-Violet. aavhines Wend 
a 50 --|-100 | 150: | 150.) 200 | 260.|-300' |-400 ||. . R. BV. 
Animal | cm. cm. 
errr 1 1 1.5 0.310 75 200 
150 300 
Be -Ob5 1 0 50 200 
ee PGS it 1 0.5 O12: 10 100 200 
bee hZeGyi Wi. 2.5 2 2.5 | 0.5 150 300 
19 3.5 | 3.5 100 250 
20 Byes cl m5 100 250 
OD (62, 5 ai. 2D 1.5 2 100 250 
24 1 2.5 75 250 
255 (1:0. | 0 ee 4 1.5 50 300 
ae laf 3 175%) 3.5 3 2 75 200 
| 100 300 
ae ey Be AO in: O)5"| 0.1 | 0 100 200 
BHP BB! |B 0.5 | | 0 150 300 
pg Cas le a GO Sel (2eh@ 0 0 50 150 
Av 95 243.3 
a = 7892.56 in terms of distance. 
BV = (2.56)? R. in terms of intensity, or 
Equation I:BV =65R 
vt II: BV = 5.6 R on rejecting G, K, 24, 25, 35 and 36. 
records first and then averaging these, yielded BV = 7.2 R; and 
when this was included with the other determinations, the final 
average expression for blue-violet in terms of the efficiency of red, 
ascertained by increasing the period of exposure, became 7.4, a value 
which is somewhat higher than that previously determined (5.6) by 
varying the intensity. 
