126Firstly, the proprietor of a series of earlier registrations must furnish proof of use of all the marks belonging to the series or, at the very least, of a number of marks capable of constituting a ‘series’. For there to be a likelihood of the public s being mistaken as to whether the trade mark applied for belongs to the series, the earlier marks forming part of that series must necessarily be present on the market. Since taking into account the serial nature of the earlier marks would entail widening the scope of protection of the trade marks forming part of the series, considered individually, any assessment in the abstract of the likelihood of confusion, based solely on the existence of several registrations covering marks reproducing, as in this case, the same distinctive element, and in the absence of any actual use of the marks, must be regarded as excluded. Consequently, failing proof of such use, any likelihood of confusion entailed by the appearance on the market of the trade mark applied for will have to be assessed by comparing each of the earlier marks, taken individually, with the trade mark applied for.