1914] JOLIV ETTE—PILOBOLUS Iit 
strip on either side of them (table IV), showing the remarkable 
precision with which the sporangium is thrown toward a light. 
A series of experiments was made to test the relative efficiencies 
of a tungsten and a tantalum lamp in bringing about a reaction of 
Pilobolus; 40-watt lamps of each kind were used. The tungsten 
was placed before the left opening, the tantalum before the right 
opening at a distance of 40 cm. 
TABLE V 
_ dl 
83 EF 
Total ZF cid 
gg BS 
= al 
373 |---| I |...| r }...| 12] sol 137] 56] 25] rol xi 3/13] 2| 6 as! St} t7| St 
ON Peislee tivatis th Bal I5|T0o| 243/100] 32) 5 4/514 5) FOL 34): 34), F713) S 
MOE Peele teeshe fe) eal Pat eS) 4 31475 1° Sb ap-a8) gol 25) 2 
32m j...|-..]...]...]...1 7] 36] xogl 42] si. rg eee ed cee Se a ee ee 
BOs foe eter | eh os] 6x eae Aa | ane, ae ed a Tf. Al 3S SQL a 
Be hes ta) 218 t) 8h 361 6 B58) SOR Ete ee en LL ee 
688 |.. --| 3] 20}112] 291/102] 19] 6) 2| 2| 2| 2] 5] 20] 47] 24 
836 <++f SO|T76| 3O3|tg8| Sri go]: xr] 4 | 2 | S| t| %4]. 22) OF 2} EF 4--- 
574 3 5] 15} 69] 248) 53] 18} 2} x}... I} 5] 24) 43) 23) 2) t) ft 
togt |...|...|...| 6 | 20] 46/156] 354|164) 46| 21) 8| 7 | 8 | 13) 20] 40] 14%) §1| 15] 5 |... 
464 |...) 2) x] 5{ a} 2x! 8x] 266] 71| 20] t7| 31213] 3 8 27, 9 old He 
BOF cl ---| 3] 17] 82| 143] 28] 25| rs} 7) 1 pee ae eed ad 
In the first experiment, 373 sporangia were discharged on the 
glass, 294 toward the tungsten and 79 toward the tantalum. The 
second experiment showed a total number of 628 sporangia, with 
516 and 112 toward the tungsten and tantalum respectively. The 
number of sporangia discharged in the third experiment was 206; 
of these, 118 were fired toward the tungsten and 88 toward the 
tantalum. The total number of sporangia in the fourth experi- 
ment was 321, 197 and 124 being fired toward the tungsten and 
tantalum. In the fifth experiment, 185 were discharged, 130 
toward the tungsten and 55 toward the tantalum. The sixth 
experiment also showed a larger number had been fired toward the 
tungsten. The data for this set of experiments are found in 
table V. 
The accuracy of aim toward the tungsten and the tantalum 
lamps was compared as in the preceding experiments. In the first. 
experiment 46.6 per cent were discharged toward the tungsten, 39.2 
per cent toward the tantalum. In the second experiment the 
