30 
Psyche 
[March-June 
Figure 5. Frequency of building of the FG and SG males of set II. 
Dashed line: weekly mean frequency of building for the 11 FG males. 
Dotted line: weekly mean frequency of building for the three SG males. 
Note similarity to Fig. 3. 
in temperature following a temperature minimum, weather condi- 
tions, barometric pressure, a full silk supply, hunger (Witt, et al ., 
1968). In the laboratory, all the spiders were subjected to the same 
environmental conditions, therefore the differences in rate of building 
should be due to an internal state, such as hunger. There is a gen- 
eral agreement in the literature that hunger is a strong drive for 
web-building. Heavy feeding is followed by several days without 
web-building (Koenig, 1951; Wolf & Hempel, 1951; Wiehle, 1927; 
Peters, 1932). The interpretation is that the hunger drive is too low 
for releasers like temperature and light to operate. On the other 
hand, spiders deprived of food built almost every day (Peters, 1939) 
and built webs even at the expense of other body constituents (Witt, 
1963b). We may assume that the FG males have a higher level of 
hunger than the SG males, which induces a higher rate of building. 
Pood consumption 
Each time a spider was fed, the fly was weighed before eating. 
Since only one or two percent of a fly was rejected by a spider after 
