LOOMIS SAYLES MID CAP GROWTH FUND CLASS MUTUAL FUNDS USMF - What does LOOMIS SAYLES MID CAP GROWTH FUND CLASS MUTUAL FUNDS USMF mean? - What does LOOMIS SAYLES MID CAP GROWTH FUND CLASS MUTUAL FUNDS USMF stand for? - LOOMIS SAYLES MID CAP GROWTH FUND CLASS MUTUAL FUNDS USMF meaning