How we cite our quotes:
The deep-laden boats pull in against the coast where the canneries dip their tails in the bay. The figure is advisedly chosen, for if the canneries dipped their mouths into the bay the canned sardines which emerge from the other end would be, metaphorically, at least, even more horrifying (0.2)
You're right, this sentence doesn't have anything to do with writing. We put it in here because this violent and gross process of canning sardines is totally the opposite of how Steinbeck says you ought to capture sea life and stories: gently, and without totally destroying them.
How can the poem and the stink and the grating noise—the quality of light, the tone, the habit and the dream—be set down alive? (0.3)
Okay, since when have poems, stinks, noises, light, tones, habits and dreams been alive in the first place? Well, Steinbeck probably doesn't mean that these things are literally alive. We're thinking he means that reader won't really feel these qualities if he doesn't write them down just right.
When you collect marine animals there are certain flat worms so delicate they are almost impossible to capture whole, for they break and tatter under the touch. You must let them ooze and crawl of their own will onto a knife blade and then lift them gently into your bottle of seawater (0.3)
Steinbeck isn't just going off on a tangent about flat worms (though he also kind of is), he's trying to tell us that collecting these worms is like trying to get down all of these super delicate qualities of Cannery Row down on paper. You have to let them ooze, and it probably helps if there's some liquid involved.