November, 19 lo 



AMERICAN HOMES AND GARDENS 



439 



Cells with pupae (magnified) 



like her, each is 

 armed with a 

 sting. But they 

 are markedly in- 

 ferior in size; 

 while, if we in- 

 quire closely into 

 their physiolog- 

 ical endowments, 

 we shall find 

 that they are im- 

 perfectly de- 

 veloped, and do 

 not lay eggs. 

 In fine, they 

 come into the 

 world for the 

 sole purpose of performing the menial labors of their colony. 

 Hence, they are usually termed "workers." With the ad- 

 vent of the workers, whose numbers are swelled daily as 

 grub after grub reaches maturity, the queen-mother ceases 

 to make paper, and devotes all her energies to egg-laying. 

 The workers take over the feeding and cleaning of 

 the grubs, as well as the extension and repairing of 

 the nest. They fly hither and thither over the countryside, 

 gathering food and building material; so that as the sum- 

 mer advances the kingdom and its population grow apace. 

 The original comb is widened, new combs are suspended 

 by paper stalks one from another, while layer after layer 

 is added to the protecting cover. 

 Moreover much time is devoted to 

 the enlargement of the hole, the 

 workers removing just enough earth 

 from day to day to accommodate the 

 increasing bulk of the nest. The 

 smaller particles are carried out 

 bodily, a task involving much toil, 

 for the passage connecting the nest- 

 hole with the open air may be sev- 

 eral feet in length, while stones and 

 pebbles of size, being undermined, 

 gravitate to the floor of the cavern. 

 The paper cells are cleared and used 

 again and again for rearing succes- 

 sive relays of grubs. But, as the 

 colony multiplies, and demands more 

 standing room at night or in rainy 

 weather, the cell structure is cut 



away from the upper and oldest comb, and a commodious 

 hall is thus provided, wherein the adult wasps congregate 

 for rest and warmth. 



A thriving wasp kingdom may shelter as many as twelve 

 hundred individuals of all ages, each one a direct offspring 

 of the original queen. 



It is a peculiarity of wasp architecture that although the 

 nest is being continually enlarged, it never appears unfin- 



A. buildin? entrance; B, attachment to root; C. lateral galleries; 

 D. entrance to nest 



^sm 



Cells with mature wasp grubs (magnified) 



Newly fledged wasp 



The outer 

 is always 



ished. 

 case 



round, shapely, 

 and perfect ly 

 closed — save for 

 the single en- 

 trance hole. As 

 the combs grow 

 laterally day by 

 day, the protect- 

 ing cover is cut 

 away from 

 within and re- 

 placed by fresh 

 layers from with- 

 out. Obviously 

 this plan necessi- 

 tates a much greater expenditure of labor and material 

 than would be the case if the structure were planned in 

 the first instance on a larger scale, especially as the wasps 

 rarely re-make the old paper. But the nest must be kept 

 constantly closed so that the grubs may be protected from 

 cold and draught. Thus it comes about that the space oc- 

 cupied by a wasps' nest is filled twice over; first by the outer 

 cover, then by the combs of cells. 



Let the reader imagine for a moment that he has entered 

 the wasps' kingdom, and is about to be "shown over" by 

 one of the bustling workers. He will realize at once that 

 he is in a topsy-turvy realm; for as he stands upon the 

 smooth upper surface of one comb, 

 and looks vertically upward, he sees 

 right into the cells of the comb next 

 above. Some of these cells contain 

 eggs, other grubs in various stages 

 of growth, while still others are 

 closed to the eye by caps of spun 

 silk. In these last are hidden wasp 

 pups undergoing their final trans- 

 formations. 



Why the wasps should have chosen 

 this head-downward method of rear- 

 ing their babies, in contrast with the 

 horizontal cell arrangement favored 

 by the honey-bee, is a mystery, espe- 

 cially as it involves one obvious dis- 

 advantage. We have seen that the 

 queen glues the egg to the side of the 

 shell. When the grub hatches, it re- 

 mains for a time with its tail in the egg-shell, moving freely 

 upon this pivot, and craning its head towards the mouth 

 of the cell to receive food from its nurses. But as it in- 

 creases in bulk, it must change its position in order to avail 

 itself to the full of the accommodation offered by the cell. 

 Now the grub has only two prehensile organs, to wit, its 

 jaws and a kind of sucker foot at its tail-end. Thus, if it 

 relaxes its hold at one extremity before making fast at the 

 other, it naturally falls headlong from the cell. Such catas- 



Egg and first stages 

 of pupae growth 



Ideal section through wasp nest 



Growing wasp grub (magnified) 



Full grown wasp grub (magnified) 



