VII PARTHENOGENESIS 253 



do much harm. Whilst Siebold was endeavouring to 

 remove some of the water from a nest which had been 

 drenched in a shower, he was astonished to find the 

 wasps themselves already busy at the work, putting 

 their heads into the cells, sucking up the water, then 

 passing to the edge of the nest and spitting out the 

 fluid. In this way they are able to get rid of the 

 effects of a wetting if it is not very severe. Though 

 the Polistes feed their young exclusively with animal 

 food, they yet appear to collect a sweet fluid which 

 Siebold found in some cells, and which he thinks the 

 workers take for their own enjoyment, since they were 

 seen entering such cells and apparently sucking at the 

 contents in fact, taking a little refreshment in the 

 intervals of their labour. 



The development of the grub is carefully described 

 by the author, and a " pseudo-nymph " stage is recog- 

 nised intervening between the nymph and the pupa. 

 The perfect insect bites off the lid of its cell, and 

 comes out with perfect wings, deposits first of all a 

 drop of urinary excretion, and makes a trial flight, 

 then returns to take part in the labours of the colony. 

 The cell is often used again for another egg. The 

 first drones make their appearance with the beginning 

 of July, an important fact for Siebold's experiments, 

 for if the nest is to be used at all now is the latest 

 moment ; they have to be killed off, and all the remain- 

 ing larvae and pupae destroyed in order to secure a 

 colony consisting solely of virgins. The drones play 

 a pitiable part in the nest sneaking about in the 

 empty cells and behind the comb. Not till the month 



