They answered, that when the cheese by its own figurative motions was changed into maggots, it was no more cheese. The Empress confessed that she observed nature was infinitely various in her works, and that though the species of creatures did continue, yet their particulars were subject to infinite changes. But since you have informed me, said she, of the various sorts and productions of animal creatures, I desire you to tell me what you have observed of their sensitive perceptions? Truly, answered they, your Majesty puts a very hard question to us, and we shall hardly be able to give a satisfactory answer to it; for there are many different sorts of creatures, which as they have all different perceptions, so they have also different organs, which our senses are not able to discover, only in an oyster shell we have with admiration observed, that the common sensorium of the oyster lies just at the closing of the shells, where the pressure and reaction may be perceived by the opening and shutting of the shells every tide.