656 THE POPULAR SCIENCE MONTHLY. 



all this and much more which I cannot stop to recapitulate. You are 

 also doubtless familiar with the still more wonderfully organized com- 

 munities of ants, with their queens, their domestic laborers, and their 

 warriors. You have heard of, if you have not watched, their maraud- 

 ing excursions, their fierce but well-ordered battles, the triumphal 

 return of the victors laden with spoil, and with captives whom they 

 reduce to the condition of domestic servants. I barely mention these 

 examples because they are familiar to all, but I must describe more 

 fully one case of instinct from the same family, which is probably less 

 familiar to you and yet no less wonderful : I refer to the case of the 

 common mud-wasp or clay-dauber. 



These insects do not form organized communities, and therefore 

 have no neuters or workers, but each female works for herself. Neither 

 does she feed her young as do bees and other wasps, but provides 

 appropriate food in abundance, and leaves them to themselves. But 

 the mode of building her cells and supplying the appropriate food 

 exhibits a marvelous wisdom. She gathers wet clay in pellets about 

 the size of a duck-shot and commences to build. Going and coming 

 from her clay-quarry to her work, with great patience, industry, and 

 skill, she builds two or three cells side by side, two or three inches 

 long and about half an inch in diameter. When finished she pro- 

 ceeds to fill them with food. For this purpose she attacks all varie- 

 ties of spiders, stings them, plunging her sting with the greatest 

 precision directly into the principal nerve-ganglion, and, after laying 

 an egg in the body of each, carries them ofi" and packs them away 

 in the cells, until these are completely full, then seals them with 

 clay and leaves them. In due time the eggs are hatched, the larvae 

 feed upon the spiders, until they become perfect insects, and cut their 

 way out of the cells. 



Observe, then, first, the walls of the cells must be thin and composed 

 of porous materials, otherwise the eggs could not hatch, nor the larvse 

 continue to live, for want of oxygen ; second, the spiders must be help- 

 less hut not dead. If they were dead they would decompose or else 

 dry up before they could be used as food. If, on the other hand, they 

 were alive and active, they would destroy each other, a;id the con- 

 tained eggs, and perhaps escape from the cell. But the poison is so 

 adjusted as to quantity, and probably as to the place of insertion, as to 

 produce a state of complete helplessness, a deep and permanent coma: 

 the spiders are as it were chloroformed by the poison. If touched or 

 irritated, they move only enough to show that they are not dead. As 

 a boy I have many times watched these wasps gathering their mate- 

 rials, building their cells, gathering their food-supply of spiders. I 

 have many times broken open their finished cells and found them full 

 of spiders in the condition described. If one desires to study spiders, 

 he can gather more varieties in one day, by breaking open the cells of 

 mud-wasps, than in a year in any other way. 



