What mean "Note that in the Bath constructor, a statement is executed before any of the initializations take place."?
Can you explain also explain phrase "before you send a message to an object reference"?
If I am understanding your question, when you create an Object, a Constructor is called. I think it's saying that some code is ran inside the compiler prior to the Constructor being called. If you don't have a Constructor defined then the system will use the 'default' one.
In Object-oriented Programming (OOP), a program is a bunch of Objects communicating with each other (paraphrased from the book). With that in mind, your Methods 'communicate' with other Objects. So, the message in this context, I believe, is any 'Call' made to an Object reference (and not the actual Object itself). I hope this helps.
I'm pretty new at this but these are me thoughts....I'm reading the same book but I'm not as far as you.