This percipient event is roughly speaking the bodily life of the incarnate mind.

But this identification is only a rough one.

For the functions of the body shade off into those of other events in nature; so that for some purposes the percipient event is to be reckoned as merely part of the bodily life and for other purposes it may even be reckoned as more than the bodily life.

In many respects the demarcation is purely arbitrary, depending upon where in a sliding scale you choose to draw the line.
I have already in my previous lecture on Time discussed the association of mind with nature.

The difficulty of the discussion lies in the liability of constant factors to be overlooked.