Tickets for the annual spring concert and centennial ball of the Pierian Sodality, to be held in Sanders Theatre and Memorial Hall April 10, will be put on sale this morning at the following prices: reserved seats in Sanders Theatre, $1.50, and 75 cents each; tickets of admission to Memorial Hall (for holders of concert tickets only) $1 each. Application blanks may be obtained at Leavitt and Peirce's, the Co-operative, Thurston's, and the Union. Applications enclosing the proper amount with an addressed and stamped envelope should be sent to C. C. Trump, manager, Fairfax 22, Cambridge, and will be filled in the order in which they are received.