Box of 64 coloured 'slides', no maker marked, possibly for a colour discrimination test .British Psychological Society ( Inv. No. 0035)
Box of 64 coloured 'slides', no maker marked, possibly for a colour discrimination test (BPS Inv. No. 0035)
Box of 64 coloured 'slides', no maker marked, possibly for a colour discrimination test (BPS Inv. No. 0035)