66 
Psyche 
[Vol. 87 
correlation was observed between the amount of silk in each of the 
ten ranges and fecal deposition (Spearman’s rho, p=0.71, p<.025; 
Fig. 2,3). These data suggest that excreta were relatively evenly 
distributed throughout the container. Comparing the observed 
distribution of fecal material with the expected based on silk density, 
however, resulted in a significant deviation with too few excreta 
found at the extreme ranges (x z =20.7, p<.02; Fig. 4). The 
distribution of excreta as related to the silk-density distribution is 
referred to as my “Model 1 approximation”. 
In a similar manner, the distribution of the spiders’ last positions 
(dead animals) was analyzed. These data indicated a clumped 
distribution as related to silk density (x 2 = 106.0, p<.001) with the 
lower silk densities exhibiting too few spiders and the high-density 
silk locations, an excess number of spiders. When the expected 
distribution of excreta was adjusted to the observed distribution of 
the animals’ last positions, too few excreta were found at the high- 
density areas and an excess was found at low-density areas 
(x 2 =249.2, p<.001; Fig 4). These data suggest that animals 
eliminated wastes outside their most frequent occupation areas and 
are referred to as the “Model 2 approximation” in following sections. 
The data related to the animals’ last positions may not provide an 
accurate model of animal distribution over time as the distribution of 
these animals may have been affected by the killing process (e.g. 
animals may have abandoned their normal living areas during 
refrigeration). Such distributions (Fig. 2) were not typical of those 
observed in living colonies, as these colonies usually had a majority of 
the animals located in the periphery areas of the container. Figure 3 
shows the distribution of living animals over time. Note that the scale 
is not linear but that the data have been transformed to Log e (Xi 
Without such a transformation, the entire central area and much of 
the periphery would show zero occupation. Nonetheless, animals 
were recorded as occupying matrix elements in the periphery of the 
container for the majority of the time and a positive correlation was 
observed between the time each position was occupied and that 
position’s silk density (Pearson’s r, r=+0.53, pC.OOl). Such a 
distribution of animals was expected based on casual observations of 
spiders in a variety of containers including petri dishes. These data 
suggest that the distribution of live animals was more contagious 
than might be expected from the above results based on the animals’ 
last position. When the expected distribution of excreta was adjusted 
