Sonic Hedgehog

123456789
Across
  1. 3. Bone placement
  2. 6. Author of inner fish
  3. 8. survival
  4. 9. frogs
Down
  1. 1. Fingers
  2. 2. Theory of _____
  3. 4. Wrist development
  4. 5. shark
  5. 6. hedgehog gene
  6. 7. Fish movement