Members of the Lewis Carroll Society of North America can download the latest Knight Letter from members-only page. There also is some Snark in there. № 106 is not available to the public in archive.org yet, so I blurred the text in the screenshot.
But perhaps Holiday’s ruff – and the pose of the Fit Five drawing – was inspired by the Elizabethan drama inherent in Millais’ Boyhood of Raleigh, (1869).
Louise Schweitzer, One Wild Flower (2012)
If you want to be on the safe side, just claim that the meaning of the Snark is elusive. But to the more courageous readers I recommend Louise Schweitzer’s doctoral thesis One Wild Flower.
2017-09-04, update: 2021-03-05