iv PREFACE, 



it appears right to convert what may be obtained 

 to ufe. There is complete evidence that a deca- 

 pitated fnail will acquire a new head, notwith- 

 ftanding the numerous difcordant opinions and 

 experiments. For this celebrated difcovery we 

 are indebted to Spallanzani, v/ho has confidered 

 the various reproduftions of animals more pro- 

 foundly and comprehenfively than any other au- 

 thor : indeed, a very great portion of what is 

 known concerning them we owe to him. The 

 firft Memoir on fnails is entire ; but the fecond, 

 where the author enters copioully into his own 

 defence, is much abbreviated. It is true, all the 

 matter is preferved, but the keennefs and redun- 

 dancy, which ever attend controverfy, can give 

 no pleafure to thofe whofe more ufeful refearches 

 -are directed to fads. For of what avail are opi- 

 nions unlefs eftablilhed on facts ? Even the 

 foundeft analogical reafoning is too often to be 

 diflrufted. 



In thefe Membirs, feveral redundancies will oc- 

 cur, but it was impoffible to avoid them. M. 

 Bonnet's whole treatife may appear in this light. 

 However, in one refpeft, it may be ufeful, name- 

 ly, from the apparent corrednefs of the engrav- 

 ings. It is by figures chiefly that we are more 

 eafily enabled to underftand fuch intricate fubjefts 

 of natural hiftory ; M. Bonnet's are more diverfi- 



fie(4 



