diff --git a/src/components/GameField.js b/src/components/GameField.js
index 2978b36..ce43565 100644
--- a/src/components/GameField.js
+++ b/src/components/GameField.js
@@ -1,18 +1,22 @@
 import Cell from "./Cell";
 
 export default class GameField {
-  constructor(seed) {
+  constructor({ fieldArray = [], fieldMap = {} }) {
     // seed = [ [] ]
     this.map = {};
-    seed.forEach((subArray, majorIndex) =>
+    fieldArray.forEach((subArray, majorIndex) =>
       subArray.forEach((value, minorIndex) => {
         if (value > 0) {
           this.map[`${majorIndex}-${minorIndex}`] = new Cell(true);
         }
       })
     );
+    for (let key in fieldMap) {
+      this.map[key] = new Cell(true);
+    }
     // instead of implementing multiple GameFields, clear irrelevant keys and expand Game Field as needed
+    // discrete Field expansion should only happen in View (to keep view fields centered)
   }
 }
 
-// as a stream -> fieldStream => Stream(GameField, () => Stream(GameField.computeNeighbors(), () => Stream(GameField.setLiving()))
+// as a stream -> fieldStream => Stream(GameField, () => Stream(fieldStream.computeNeighbors(), () => Stream(fieldStream.setLiving()))
diff --git a/src/test/GameField.test.js b/src/test/GameField.test.js
index 6f620b2..71605be 100644
--- a/src/test/GameField.test.js
+++ b/src/test/GameField.test.js
@@ -6,19 +6,34 @@ describe("Game Field", () => {
   });
 });
 
-describe("Game Field seeds living Cells", () => {
-  const gameField = new GameField([
-    [0, 1, 0],
-    [1, 0, 1],
-  ]);
-  [("0-1", "1-0", "1-2")].forEach((key) => {
-    test(`${key} should equal living Cell`, () => {
-      expect(gameField.map[key].living).toEqual(true);
+describe("Game Field seeds living Cells with array", () => {
+  const gameArraySeed = new GameField({
+    fieldArray: [
+      [0, 1, 0],
+      [1, 0, 1],
+    ],
+  });
+  const gameMapSeed = new GameField({
+    fieldMap: {
+      "0-0": true,
+      "0-2": true,
+      "1-1": true,
+    },
+  });
+  ["0-1", "1-0", "1-2"].forEach((key) => {
+    test(`Array seed: ${key} should equal living Cell`, () => {
+      expect(gameArraySeed.map[key].living).toEqual(true);
+    });
+    test(`Map seed: ${key} should equal undefined`, () => {
+      expect(gameMapSeed.map[key]).toEqual(undefined);
     });
   });
   ["0-0", "0-2", "1-1"].forEach((key) => {
-    test(`${key} should equal undefined`, () => {
-      expect(gameField.map[key]).toEqual(undefined);
+    test(`Array seed: ${key} should equal undefined`, () => {
+      expect(gameArraySeed.map[key]).toEqual(undefined);
+    });
+    test(`Map seed: ${key} should equal living Cell`, () => {
+      expect(gameMapSeed.map[key].living).toEqual(true);
     });
   });
 });