112 BOTANICAL GAZETTE [FEBRUARY 
percentages fired toward the tungsten and tantalum were respec- 
tively 47 and 33.5. The third experiment shows 60.1 per cent 
before the tungsten and 44.3 before the tantalum; the fourth, 52.7 
and 49.1 respectively; the fifth, 46.9 and 43.6; and the sixth, 48.9 
and 44.8. The tenth and twelfth experiments show slightly larger 
percentages on the opening before the tantalum. The percentages 
figured out for the numbers striking either opening are given 
in table VI. The larger percentages strike the opening before the 
_ tungsten in these experiments. Most of the sporangia missing the 
opening strips in these experiments were found in the adjacent 
I-cm. strips, as was the case in the foregoing experiments. 
TABLE VI 
Numbe: P. t = Numbe P t: Percentages 
so foe | eee rs eee ee 
experiment tungsten lamp | tantalum lamp experiment tungsten lamp | tantalum lamp 
to 46.6 39.2 7 ag oe eee 44.3 42.7 
Se ere eee 47 33-5 Bo ess 41.3 
Be ic ees 60.1 44.3 Bee 59-5 4 
Be Oye Sou 49.1 i ie nee ore 42.9 47.6 
eae eae 46.9 43-6 i Catteni sce At] 40.9 
Oe scccen oe, 48.9 44.8 OCR ae 44.2 50.7 
In the next series of experiments a 40-watt tantalum was placed 
before one opening and a 20-watt tungsten before the other. The 
total number of sporangia fired in the first experiment was 1004; 
731 were on the half of the glass toward the tantalum and 273 
are on the half toward the tungsten. 
The second experiment shows a total discharge of 407 sporangia, 
329 on the tantalum as against 78 on the tungsten. The third and 
fourth experiments both show larger numbers on the.tantalum. 
The data for this set of experiments are found in table VII. The 
accuracy of aim toward the two lights may also be obtained from the 
data in this table. Of the 731 sporangia discharged toward the 
tantalum lamp in the first experiment, 420 (54 per cent) struck the 
1-cm. strip containing the opening. Of the 273 fired toward the 
tungsten, 149 (54 per cent) were on the corresponding strip. In 
the second experiment, the number of sporangia fired toward the 
tantalum lamp was 329; of these 161 (49 per cent) were in line with 
the opening. The total toward the tungsten was 78, with 37 
