无法使用PHP检索某些cookie

I've got to be missing something simple, but this is driving me batty.

I'm setting a whole bunch of array cookies, like so:

setcookie("adjusted[$title]", $title, time() + 3600, "/", ".domain.com");

This works just fine, the cookies are being set and I can see them in the browser's cookie list.

However, I can't seem to read only certain values back out! I have no idea why. For example, I set this cookie:

adjusted[calldelivernow.net]

and I can see that is its name in Firefox's cookies page, the content is "calldelivernow.net". But all attempts to do this return false:

if(isset($_COOKIE["adjusted"]["calldelivernow.net"]))
    die("Cookie is set");

This is just one example of many, all under identical parameters just with different domain names. What on earth am I missing here? How can a cookie plainly exist in the browser, yet PHP not be able to read it?

Because you're not calling it by it's name correctly. Unlike form names, cookies do not get stacked to arrays.

Try $_COOKIE["adjusted[calldelivernow.net]"].

The problem appears to be that cookie names, cannot contain periods! Strangely, Firefox is in fact showing that the cookie name is correct and contains the period, but the $_COOKIE array replaces the period with an underscore, like so: ["calldelivernow_net"]=> string(4) "test"