DIPTERA OF MINNESOTA. 



99 



larvK living in the filth of the barn yard or privy. Particularly is this 

 true of ErisfaUs tcmi.v, whose larva is commonly known as the Rat- 

 tailed Maggot, a name proposed by Reaumur years ago, and still 

 retained. This species lives in foul pools wherever decaying organic 



ijir'^i?^ ^^'Vx 



y a ^^ 



Fig. 92. Syrphiis ribcsii. Original. 



Fig. 93. A Syrphid larva feeding on 

 plant lice. Original. 



matter is present. In this maggot the so-called "tail" is a tube used 

 in respiration, and capable of being extended to the surface of the 

 water for that purpose. The adult Bristalis resembles a bee so closely 

 that the ancients, seeing swarms of this genus coming from the putri- 

 fying carcasses of oxen, believed that bees could be produced from such 

 dead bodies. Ovid, Virgil and other ancient winters, by their works, 

 gave color to this belief, but Florentinus, a Byzantine author of 

 about the tenth century A. D., gave the most explicit directions for 

 producing bees from such sources, and Osten Sacken translates his 

 statements as follows : 



"Build a house, ten cubits high, with all the sides of equal dimensions, 

 with one door and four windows, one on each side; put an ox into it, thirty 

 months old, very fat and fleshy; let a number of young men kill him by beat- 

 ing him violently with clubs, so as to mangle both flesh and bones, but tak- 

 ing care not to shed any blood; let all the orifices, mouth, eyes, nose, etc., be 

 stopped up with clean and fine linen, impregnated with pitch; let a quantity 

 of thyme be strewed under the reclining animal, and then let windows and 

 doors be closed and covered with a thick coating of clay, to prevent the access 

 of air or wind. Three weeks later let the house be opened, and let light and 

 fresh air get access to it, except from the side from which the wind blows 

 strongest. After eleven days you will find the house full of bees, hanging to- 

 gether in clusters, and nothing left of the ox but horns, bones and hair. When 

 the shed is opened, small white animalcules are seen, resembling each other, 

 motionless; then they are observed to grow little by little, to develop wings, 



