2o6 THE CULTURE 



weather, they by thefe means have ftelthef 

 the advantage of air or exercife ; their 

 food is conftantly fupphed, and they are 

 pampered and full fed without having any 

 labour of fearching about and going from one 

 branch to another, which they are obliged 

 to do in their natural ftate. Now though 

 this method of your fupplying them with 

 food is unavoidable, and though it may 

 for the prefent make them large, and pro- 

 duce a great quantity of filk, yet I think 

 it mufl at length caufe the breed to be lefs 

 healthy, and lefs fit for propagating fo 

 ftrong and vigorous, or fo numerous an 

 offspring as the worms which enjoy a free 

 air, and are forced to move about and hunt 

 for their food : for I believe it will be al- 

 lowed that if a cock and hen were con- 

 fined to breed in a coop, and their offspring 

 to do the fame, the breed would foon lofe 

 its mettle, and degenerate. 



To prevent this degeneracy in the health 

 and vigour of fiikworms, and to continue 

 the breed in full perfe6lion, I would pro- 

 pofe an experiment, viz. that a few might 

 always be bred Vvild on the mulberry-tree, 

 with the beft of which you might crofs 

 the flrain of your own breeders. To ef- 



