The Board of Directors may appoint a manager who may be, but who shall not be required to be, a member of the Cooperative, but shall become a member as soon as practicable. The manager shall perform such duties and shall exercise such authority as the Board of Directors may from time to time vest in him and, in general, is responsible for those external and internal affairs and activities of the Cooperative incident to and appropriate with ordinary and regular course of the Cooperative's business.