THE SOCIAL INSECTS 



on a comb with different coloured paints so that each one 

 can be recognised. It is then found that one individual, the 

 queen, stays in the nest and does all or almost all the egg- 

 laying. She receives a relatively large share of the food 

 brought in by the foragers. The workers do all the food and 

 paper gathering and most of the nursing. The workers are 

 rather smaller than the queen, on the average, but there is a 

 wide overlap in size. If the wasps are dissected, the queen is 

 found to have a much better-developed ovary and to have 

 sperm in the receptacle where they are stored. Neither of 

 these features, however, may be present in the young autumn 

 queens before hibernation, and these can be distinguished 

 from the workers only by their inactivity. The workers' 

 ovaries are smaller than those of the old queen though better 

 developed than in the workers of the common wasp. Workers 

 are never fertilised. No special queen cells are made when the 

 colony is mature. 



Deleurance, who has kept nests in his laboratory in Paris, 

 has shown that if the queen is removed the workers may 

 begin laying male-producing eggs within twenty-four hours. 

 This proves that their failure to do so in the ordinary way 

 is not because they are unable to lay eggs, but because their 

 egg-laying is inhibited by the presence of the queen. This 

 inhibition may be partly due to active interference by the 

 queen. To lay an egg a wasp has to enter a cell backwards, 

 and this action might stimulate the queen to threaten or to 

 attack. In nature the queen is rarely observed to make such 

 attacks, and probably her mere presence inhibits egg-laying 

 by the workers. This interpretation is supported by Pardi's 

 observations in Italy. In many nests the queen dies rather 

 early in the history of the colony, and the workers then begin 

 laying eggs. Pardi found that in late summer some nests 

 produce queens and males in about equal numbers, whereas 



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