1980] Tietjen — Sanitary Behavior of Malios gregalis 
67 
to the model based on the distribution of living animals over time, a 
significant deviation was observed (x 2 =5960.3, p<.001), as 
approximately 86% of the fecal material would be expected to be 
found in the areas of highest silk density (Fig. 4). These data are 
referred to as the “Model 3 approximation” of expected excreta 
distribution. 
Although the meanjsilk density of the small vs. the large containers 
did not differ (small: (Y= 286.5± 170.2 units; large: (Y= 280.0+163.9 
units; Man-Whitney test, T = 13, ns), a positive correlation was 
observed between the number of animals in each colony and the 
observed mean silk density (Spearman’s rho, p=+ 0.84, p<.001; 
Kruskal-Wallis test, T= 6.41, p<.05). Similarly, an animal-number 
effect was observed for the number of excreta (Spearman’s rho, p = + 
0.82, p <.005). Therefore, an increased number of animals deposit 
both more silk and more fecal material (Table 1); however, these 
results do not affect the above analyses as the distribution of excreta, 
animals and silk did not differ among colonies of varying size or 
between container sizes. 
Discussion 
I. Evaluation of Methodology 
The apparatus cannot recognize structural features of the web (e.g. 
chambers and tunnels) but instead describes the web as a series of 
points having differing silk densities. As such structures tend to be 
enveloped in dense silk, however, the data do reflect the relative 
complexity of one area over another. Using methods similar to those 
used to record excreta positions, one could record the distribution of 
structural features within colonies. 
The testing of the colonies in a relatively confined space has both 
advantages and disadvantages. An obvious objection is related to the 
“unnaturalness” of the laboratory situation. In the field, however, as 
the animals roll leaves to support the web structure, one might expect 
the construction of similar confined spaces. A decided advantage of 
confinement is a reduction in web-shape variability among colonies 
thus allowing detailed statistical analyses with reasonable sample 
sizes. Such webs, although built in a confined space, are typical when 
compared to those built in larger containers. Hollar et al. (in review) 
indicated that M. gregalis prefer to build in the corners of various¬ 
sized containers (ranging from small glass vessels to room-sized 
environments). The utilization of the petri dishes by the spiders in 
