A NATURALIST IN BRAZIL 



SO that the whole constitutes a sort of comb covered with a domed 

 roof of clay. Among the enemies of the Pill-wasps are the Golden 

 Wasps, small insects whose bodies have a green, blue and red 

 metalhc lustre; these insects wait cautiously until the Pill-wasp has 

 flown away, when they crawl quickly into the pot, and lay their 

 egg beside that of the rightful proprietor. The latter returns, takes 

 no notice of the strange egg, completes the provisioning of the pot, 

 and seals it up. The egg of the Golden Wasp is the first to hatch, 

 and the emerging larva quietly devours the egg of the Pill-wasp and 

 its intended victims. 



There are Pill-wasps which do not seal their pots, but leave them 

 open. These visit their larvae, and bring them fresh prey; indeed, 

 many species even feed their larvae with masticated insects. Such 

 care of the offspring is a step towards the community of the true 

 Wasps. We have only to imagine that the mother-wasp begins to 

 build whole rows of juxtaposed cells, so that she is still feeding the 

 last larva to creep from the egg when the first of the family to 

 emerge has already pupated, or has even become a wasp. In such 

 a case it would hardly be an essential innovation were the young 

 wasp to dedicate her activities to the common home, building her 

 own cells beside it; or even were she to begin to feed the brood, 

 her maternal instincts being aroused by the sight of the hungry 

 larvae. We can very well imagine that by such premature demands 

 on the maternal instinct the erotic urge which should normally 

 precede this instinct, and ensure its development, is extinguished, 

 so that the wasp now becomes a mere female helper in her mother's 

 household. And now, if her sexual organs degenerate — as all things 

 do degenerate which are not used — so that they can no longer be 

 fecundated, the insect will become a worker pure and simple, and 

 the mother, released from the labours of cell-building and feeding 

 the larvae, and consequently able to devote herself entirely to the 

 business of laying eggs, may now be called a "queen." 



In the Field-wasps common in Europe and America — most of 

 them barred with black and yellow — we find the early stage of such 

 a communal State. The female masticates wood and similar sub- 

 stances, and produces a material not unlike blotting-paper, with 

 which she at first constructs a short tube or brood-cell, adhering 

 to a wall or the trunk of a tree. To this first short tube others are 

 added, and the better to economize space the walls are flattened, 

 so that the tubes become hexagonal ; and so we have a comb, con- 

 sisting entirely of cells hanging from a short stalk. In the American 

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