Page:The Zoologist, 4th series, vol 3 (1899).djvu/388

360 their own making, as to distrust the evidence of my own senses respecting the existence of a pre-established and duly-considered system in nature, the arrangement of which preceded the creation of all things that exist."

What we seem to require is a healthy Agnosticism in theoretical science; neither affirmation nor negation, per se, but proof. Thus, grant to all a free use of the imagination in scientific theory, but in no case allow it to be confounded with fact, or crystallized into dogma. "What is called 'mimicry' is apparently, in many cases, nothing more than the influence of similar surroundings, acting in a similar manner upon different insects inhabiting the same district." Or, as Mr. F.T. Mott most enigmatically puts the objection, "The very curious appearances of mimicry, which are often supposed to be protective, but of which a large proportion seem to have no such function, may probably be attributed to sympathetic communication of the vibratory motions which must be passing through the ether in all directions in the neighbourhood of organic life." Animal depredators may, however, be not altogether defeated by "mimicry," which of course predicates the sense of sight only. As Mr. Cornish has well observed, predaceous animals watch for movement to guide them to their prey. "Most of the larger birds, notably Wood Pigeons, remain perfectly motionless for many seconds after alighting in a new place, in order to identify any moving object. On the other hand, the power of scent is a great corrective to animal misconceptions about objects." How little is the cause of Darwinism advanced by many exhibitions made at scientific societies! The advocate exhibits—say, insects—which, belonging to different orders, closely resemble each other in colour, markings, or structure, and which he reasonably adduces as an example of "mimicry," but misuses a suggestion as a demonstration. The Darwinian sceptic at once denies the strength of the whole argument, because it cannot be demonstrated as a fact, and has not been put forward as a suggestion only. It is quite possible