There are many interpretations possible, because Steinbeck chose to leave it that way. The meaning depends on two things, what the writer meant and what the reader understands. In comparing this chapter to the rest of the book, I see that the land turtle could symbolize many things: nature, the Joads, family, the working man.
Without the rest of the book it is simple: the turtle is uniquely suited to his environment as are all the seeds that grab at every passing creature. The turtle is confronted with a barrier, and it gets across, in spite of the dangers of heat and attackers.
His shell protects him. However, he does drag the wilds oat seeds with him, and he plants them as he moves away. So the cycle of life is complete.
If comparing this chapter to the rest of the book, one really strong impression is that this chapter symbolizes the story of the sharecroppers, especially families like the Joads. The land turtle is an ancient animal and he fits a specific niche. He is almost totally safe within his niche.
The road is not part of that niche, nor is the four-inch wall, and they seem to be symbols of progress and also of change and troubles. The two vehicles are dangerous. The woman avoids hitting the turtle, but does not stop to put it safely off the road, so she might be just “those good men who stand by and do nothing.”
The man driving the truck actually tries to hit the turtle for no other reason than that he is there, a target. The man hits the turtle, but his shell protects him and he is only slowed down, because he is upside-down and must right himself.
Steinbeck leaned toward socialism and the early American Communist Party held out attractive ideals for him. So he believed in the resilience and eventual triumph of the working class.
It is easy to look at the turtle as the symbol for the sharecroppers and maybe of the Joad family, but I just cannot ignore the real winner in this chapter: the wild oat. The little seed head manages to get picked up by the turtle and carried all the way across the road and finally has three of its seed planted quite nicely by the turtle.
When you think about this, weeds are the most resilient of all. Whatever passes is a vehicle for spreading their seeds. Steinbeck devotes the entire first paragraph to describing the sleeping life, ready to be spread.
Then he is careful to mention the success of the wild oat at the end of the chapter: “The wild oat head fell out and three of the spearhead seeds stuck in the ground. And as the turtle crawled on down the embankment, its shell dragged dirt over the seeds.”
Communist leaders of the time saw the working class as a sleeping giant that would awaken and take its rightful place ruling the world.
So the turtle could symbolize the sharecroppers, overcoming barriers and avoiding dangers, plodding along towards an unknown goal and spreading new ideas on their way. It could as easily symbolize the Joads. As a family they are suited to their niche, but the niche is vanishing and they must adapt.
They must overcome problems and move from one area to another. In the process they will be ignored by some and targeted by others. However, they will survive and continue towards their goal and spread new ideas on the way, perhaps help to create a new way of life.
The oat seed head is something they pick up accidentally and take with them for a time until they reach fertile ground and then it falls away and they plant it by their passing.
Any of these interpretations work, and yet, I really like the way this chapter reads all by itself. There is much I get from it that I really cannot express. It is so poetic and beautiful I will remember it.
