Cut marrow into 4 strips and then cut strips in half (you will have 8 sticks per zucchini). Place sticks in small bowl and sprinkle with salt, oregano, pepper and garlic powder. Toss until marrow sticks are coated. Place flour, eggs, and bread crumbs in separate bowls (bowls should be large enough to hold sticks). Beat eggs. Toss sticks, a few at a time in flour. Drop in eggs. Drain and then toss in bread crumbs. Pour vegetable oil in deep saucepan to depth of 6 inches. Heat oil to 350°F. Fry sticks a few at a time till golden brown, about 3 minutes. Drain on paper towels. Serve warm.