22 



of solar light decreasing the effectiveness of the artificial light. 



D 



Relative humidity was measured with a Bacharach sling psychrometer. 

 The clothespins were placed adjacent to the snail following each read- 

 ing to help relocate the snail at later time intervals. This experi- 

 ment was replicated three times over a three year period. 

 Results and Discussion 



The first experiment on August 27, 1975, showed a correlation in 

 line slope between the increasing percent relative humidity and the 

 increasing percent snail activity (Figure 1). In this case a slope (M) 

 of M=2 was found for both items. It is interesting to note that as the 

 relative humidity reached 100%, the first trace of snail activity was 

 noted. The dotted line demonstrates this phenomenon. The accompanying 

 snail activity line then proceeds at the same rate of increase as did 

 the percent relative humidity line, that is the slopes (M) were the same, 



A similar relative humidity and snail activity slope correlation 

 can be seen with the April 28, 1976, observation (Figure 2). The first 

 traces of snail activity began with the relative humidity reaching 100%. 

 Again there are the similar slopes of the lines, in this case M=4.3. 

 It would appear that the increase in relative humidity may predispose 

 or effect the ensuing snail colony's activity pattern. Similar line 

 slopes for relative humidity and snail activity were found on two of 

 the three replicates. 



On July 18, 1977, the final field observation was made (Figure 3). 

 A unique situation occurred where 96% relative humidity was maintained 

 for seven hours prior to reaching 100%. Even under this extended dura- 

 tion of high humidity the first snail activity did not begin until 100% 

 relative humidity was obtained. This would indicate a need for 100% 



