Referee's report by Alexander Craig Aitken, on a paper 'Invariant theory, tensors and group characters' by D E Littlewood Sectional Committee: Mathematics Recommended for publication in the Philosophical Transactions of the Royal Society. The paper is very long and difficult to read, 'but deeply interesting'. Refers to work of AYoung, whose work the current paper continues, and a 100 year old incompletely solved problem. Contains extra question - 'Is there any information contained in the paper which likely to be of value to the enemy?' Referee replies no. [Published in the Philosophical Transactions of the Royal Society] No received date. [1943]