'M - give it ten' ([hand] in [glove]) and 'Dr Castier' ([throw] in [the towel]) are not crossword clues, they are Dingbats. These can often be found in the junior sections of other papers and are quite enjoyable in the right place though not in the Guardian cryptic. Similarly constructed clues in which the absent definition is hinted at by the words used are legitimate, and if this is effective the question mark can be superfluous.