The shares of stock of any insurance company shall be deemed personal property and shall be transferred on the books of the company in such manner as the bylaws thereof may direct; but no transfer of stock shall be valid against an insurance company so long as the registered holder thereof shall be liable as principal debtor, surety or otherwise to the insurance company for any debt which shall be due or unpaid, nor in such case shall any dividend, interest or profit be paid on such stock so long as such liability continues, and such dividends, interest or profit shall be retained by the insurance company and applied to the discharge of such liabilities, and no stock shall be transferred on the books of any insurance company without the consent of the board of directors where the registered holder thereof is indebted to the insurance company.