48. ADVERTISEMENT OF SERIES. -Where an application of trade marks differing from one- another in respect of the particulars mentioned in sub-section (3) of See. 15, the applicant may be required to supply a printing block (or more than one, if necessary) satisfactory to the Registrar of any or each of the trade marks constituting the series; or that Registrar may, if he thinks fit, insert with the advertisement of the application, a statement of the manner in which the several trade marks differ from one another. | 