VII PARTHENOGENESIS 251 



obliged to protect those lie wished to study with 

 nets. The members of one nest are not allowed to 

 remain in another, if by chance a stranger comes in 

 she is hustled out at once by the wasps near the en- 

 trance. Siebold convinced himself of this by painting 

 the thorax of a number of Polistes belonging to different 

 nests with different colours. Only late in the year, 

 when the wasps seem to be getting careless or tired of 

 their incessant work did he find that one or two had 

 got mixed in certain colonies, to which they did not 

 rightly belong. Although there is this sharp discrimi- 

 nation of individuals, yet it was found that by sub- 

 stituting one nest for another whilst the queen was 

 away, she could often be deceived, so as to make her 

 enter upon the possession of the substituted nest as 

 though it were her own. Siebold found this a very 

 useful plan when he wanted to change the position or 

 locality of a nest so as to bring it into a safer or more 

 accessible spot, or when a nest which he had been ob- 

 serving was by some accident deserted, or when a 

 nest in a favourable position was less forward in the 

 development of its larvae than one less favourably 

 situated. By making the nests movable, and sub- 

 stituting the one for the other in the absence of the 

 queen, he was able to save himself much trouble and 

 loss. The nests were made movable by removing 

 them from their original support and firmly fixing 

 them to boards which were then hung up in the original 

 position. The queens were very anxious after this 

 operation had been performed, investigating with 

 great care the strength of the support and the cord by 



