550 Wisconsin Academy of Sciences, Arts, and Letters. 
moved further away, but this of itself does not prove conclu¬ 
sively a greater inaccuracy in aim; since a deviation of, aim of a 
few degrees from the direction of the incident light might not 
prevent a sporange from hitting the opening at short range, 
but would prevent it if the distance from the opening were in- 
* 
creased several fold. Here, however, we have positive evi¬ 
dence of greater inaccuracy of aim at long range. In each of 
these cases the sporanges have travelled 10 centimeters toward 
an opening 4 centimeters in diameter. In one case that open¬ 
ing was 10 centimeters away (Fig. 9), in the other 110 (Fig. 
8). In the first case the sporanges are well within the open¬ 
ing and the scattering ones form an almost negligible percent- 
