Symbolism, Imagery, Allegory
What do you get a guy who has everything? (If by everything, you mean babies in jars.) A quilt, because have you even seen his?:
It was covered with an old faded red blanket full of fox tails and burrs and sand, for he took it on all his collecting trips. If money came in he bought laboratory equipment. It never occurred to him to buy a new blanket for himself. (27.7)
So Dora's girls decide to make him a quilt:
Dora's girls were making him a patchwork quilt, a beautiful thing of silk. And since most of the silk available came from underclothing and evening dresses, the quilt was glorious in strips of flesh pink and orchid and pale yellow and cerise. [ . . . ] Under the community of effort, those fights and ill feelings that are always present in a whore house completely disappeared (27.7)
A patchwork quilt is made up of a bunch of little individual pieces of fabric all sewn together to make a beautiful pattern. If that isn't a good metaphor for a community like Cannery Row, we don't know what is. All the individual pieces of the community are connected to form something beautiful, something warm, something comforting.
And, like Cannery Row, this quilt is a little louche and unorthodox, too. All alone, Doc doesn't even think to get a new blanket for himself. It takes the community to realize that he needs one.