SPECTRAL ENERGY CURVES OF LIGHT EMITTED BY VARIOUS SPECIES. 23 
In view of the fact that the color of the light of Photinus consanguineus and 
Photinus scintillans appears to be more variable than that of other fireflies, 
it would be of interest to determine whether they emit light composed of two 
bands, of which the one is yellow and the other is orange-red. A large dis- 
persion would be required; and plates sensitized so as to be more uniform 
in their action in the red and yellow would be useful. 
TABLE 2. 
Photinus pyralis. Photinus consanguincus. 
i pate of Pies tio of 
ensities: D lensities: ener, A 
ae | Firefly distribution di see ot wave caswrig aigtribation Gece 
length. | oO length. fe of carbon f 
Glow-lamp glow lanip: of firefly. Glow-lamp | glow-lamp. of firefly. 
| (Big. 9). (Fig. 9). 
.0523u | 0.25 3.45 0.86 0.522p 0.2 3.40 0.68 
527 1.00 3.05 3.65 525 5 3.53 1.77 
-530 .50 3.78 1.89 -530 1.5 3.78 5.67 
534 1.50 3.98 5.97 -531 2.0 3.88 7.76 
-535 | 1.50 4.05 ,08 534 3.0 3.98 11.94 
-537 2.00 4.18 8.36 535 43 4.05 17.42 
-544 | 3.00 4.57 13.71 537 5.0 4.18 20.90 
+540 . 3.70 4.68 17.32 541 755 4.39 32.93 
553 5.00 5.07 25.35 543 6.9 4.53 31.26 
555 5.55 5.20 28.86 545 9.3 4.64 43-15 
560 7.00 5.55 38.85 548 15.0 4.80 72.00 
-570 7.20 6.24 44.92 -549 13.5 4.87 65.75 
-576 5.55 6.74 37-41 555 18.3 5.22 95-93 
-577 5.00 6.82 34.10 -560 21.6 5.54 119.66 
581 3.70 7.15 20.45 , +570 28.0 6.30 176.40 
585 3.00 7.52 22.56 -570 20.7 6.30 130.41 
587 2.78 7.68 21.35 -576 23.0 6.74 155.02 
589 2.00 7.87 15.74 . 580 26.5 7.09 187.89 
- 590 1.85 7.90 14.73 585 25.1 7.53 189.00 
.592 1.50 8.12 12.18 . 589 23.42 7.89 183 .05 
-598 1.25 8.72 10.90 -590 23.0 7.97 183.31 
601 1.00 9.03 9.03 595 15.0 8.44 126.60 
605 75 9.40 7.05 596 13.8 8.53 117.71 
615 38 10.45 3.97 598 9.2 8.72 80.20 
620 25 11.05 2.76 .600 7.5 8.90 66.78 
623 13 11.35 1.48 601 6.9 9.03 62.31 
-605 5.0 9.80 49.00 
.610 4.5 9.91 44.60 
611 3.0 10,02 30.06 
-619 2.3 10.91 25.09 
620 2.0 11.05 22.10 
624 1.5 11.50 17.25 
628 1.0 12,02 12.02 
.634 1.0 12,80 12.80 
638 5 13.30 6.65 
-648 2 14.61 2.92 
Having but one density curve (Fig. 8, 6,—%,—%) of Photinus scintillans, 
and this one being too much overexposed to work out the central part of the 
curve, no exact value of the maximum emission of this insect has been 
obtained. The density curve is symmetrical with a similar one of the 
Photinus consanguineus, and, in view of the fact that to the eye there is no 
marked difference in the color of the light (the flash) emitted by these two 
species, the maximum emission of scintillans is taken to be the same as that 
