RESEAECHES UPON SPIDERS. 59 



III. 



BASE WITH WHICH SPIDERS MAT BE FED. 



With Reaumur, a great and insuperable difficulty, is 

 that of feeding with flies such a number of spiders as might 

 yield a profitable result, "all the flies in the kingdom" he 

 says, "would not suffice to feed spiders in such a number 

 that any profit can be derived from them." But, in the first 

 place, I find that he himself ascertained that flies were not 

 the only food for spiders, having nourished them with bits 

 of earth-worms cast upon their webs, and with pieces of the 

 tender quills of 'doves and chickens, which they sucked with 

 avidity. 



In the second place, I observe that feeding the spiders 

 upon flies is not a difficult matter, since they collect in great 

 numbers when honey or any other food of that kind is placed 

 near the abodes of the spiders, either in a room or 1 out of 

 doors. I prefer the method of collecting the spiders in the 

 field and bringing them into a very light room, where, at a 

 height above a man's head, are placed some canes, to which 

 they may attach their webs. The lightness and good expo- 

 sure of the room enable them to catch their food by day, 

 and in the night they employ themselves chiefly in spinning 

 their webs, or in forming their cocoons. I think it advisa- 

 ble too, after a considerable number of flies have entered, to 

 prevent with a thin, cheap veil, the ingress of birds and in- 

 sects hostile to the spiders. 



In order that the flies may collect, I have found use- 

 ful, after repeated experiments, the method proposed twenty- 

 five years ago, namely, to put small bits of putrifying meat, 

 upon a little stand supported by a stick nailed into a box, 

 filled with pulverized earth. The female flies deposit upon 

 the flesh, eggs, which soon become larvae or maggots, which, 

 when they have reached a proper size, throw themselves or 

 fall into the earth, are changed to pupae and finally become 

 flies. If the odor of the putrid meat is objected to in the 

 room where the spiders are, it may be kept in some more 

 convenient place, where the flies can deposit their eggs, and, 

 when the worms have fallen into the earth, the box contain- 

 ing them may be put in the spiders room until the flies have 



