ss 
Gry. 
“}: 
MEMOIR IL. 
a 
INTRODUCTION. 
I KNow not whether in our days there has been 
any natural phenomenon which, from novelty 
atid fingularity, has made as great a noife in the 
phyfical world, has given birth to fo many expe- 
riments, and altogether to refults fo various and 
oppofite as the reproduction of the heads of 
fnails. Since the publication of my Predromo, 
and the tranflation of it into the French, Ger- 
man, and Englifh languages, it is incredible how 
many of thefe reptiles have been decollated ; part- 
ly by fome whofe account of their experiments 
firft imparted to the world that they exifted ; part- 
ly by ordinary naturalifts, or thofe of fome cele- 
brity, but little lefs than unfkilled in experiment, 
and partly by illuftrious naturalifts who, in the 
art of experiment, enjoy a diftinguifhed reputa- 
tion. How was it poflible that fo great a differ- 
Vor. Il. R ence 
