THE MUD-DA USERS. 199 



ance that she may encounter than to paralyze the spider and 

 thus keep it fresh. To her it is a matter of indifference whether 

 the spiders are killed or paralyzed, and either result may fol- 

 low. The examination of cells recently provisioned shows that 

 while most of the spiders are dead, many of them, although 

 motionless, are alive and will respond to stimulation by a quiv- 

 ering of the tips of the legs. These living spiders die from 

 day to day, the death rate depending upon the amount of poison 

 that has been injected. It is probable that the spiders are 

 usually stung in the under side of the cephalothorax. We base 

 this opinion upon what we ourselves have seen and also upon 

 the fact that many of the Pelopaei take spiders of the genus 

 Gasteracantha, in which this is the only part soft enough to be 

 penetrated, all the rest of the spider being enclosed in horny 

 plates; and it is commonly the fact that among the solitary 

 wasps all the members of a group sting their victims in the same 

 way. 



