INSECTS. 109 



(:ase, against Aristotle.' He advanced the propo- 

 sition, omnia ex ovo, and the most piofound and 

 elaborate investigations of philosophy have con- 

 firmed his opinions. The polype furnishes indeed 

 an argument against this doctrine. If divided 

 Into several parts, each part will become a per- 

 fect animal. I can only surmount this objection 

 by supposing each polype, as it appears in its 

 usual shape, to be a congeries of animals, aggluti- 

 nated together, and when a separation takes place 

 that complete beings will exist in a state capable 

 of enlargement. We see something analogous in the 

 vegetable world. Trees produced from the cut° 

 ting, without any sexual annexion. It is suppo- 

 sed that the weeping willow, or salix Babylonica, 

 was introduced into Europe at the time of the 

 Crusades. It was transplanted from the river 

 Euphrates about the year 1748, by Mr. Vernon, 

 a Turkish merchant, at his country seat in Eng- 

 land. The English as well as the American 

 weeping willow is a female, and exists in both 

 countries in a widowed state. It is propagated 

 from the cutting, and so is the Lombardy poplar^ 

 which is only a male in America. 



The introduction of pernicious insects ought 

 to be carefully guarded against, and yet it is 

 almost impracticable. Numbers of exotic insects 



are imported in timber and packages of c:oods» 



F2 



