| Answer | Crossword Clue |
|---|---|
| SULPHURS | Yellow butterflies, to Brits |
| SULPHURS | Yellow butterflies |
| xanthopterine | a yellow pigment obtainable from the wings of yellow butterflies and the urine of mammals also XANTHOPTERIN |
| xanthopterin | a yellow pigment obtainable from the wings of yellow butterflies and the urine of mammals also XANTHOPTERINE |
| xanthopterins | XANTHOPTERIN, a yellow pigment obtainable from the wings of yellow butterflies and the urine of mammals also XANTHOPTERINE |
| xanthopterines | XANTHOPTERINE, a yellow pigment obtainable from the wings of yellow butterflies and the urine of mammals also XANTHOPTERIN |
