Page:The aquarium - an unveiling of the wonders of the deep sea.djvu/161

120 in that singular reptile the Chameleon, and long supposed to be quite anomalous. It is that the eyes, which in most vertebrate animals move only in unison with each other, and as if by a common impulse, are here quite independent; the one glancing hither and thither while its fellow remains motionless, or looks in different directions.

A few years ago Mr. Lukis of Guernsey observed that the same peculiarity existed in the Sea-horse (Hippocampus) a curious little fish of the Syngnathidœ or Pipefish family. In my "Devonshire Coast" I mentioned the Worm Pipefish (Syngnathus lumbriciformis) as a second example of the phenomenon in this class of animals; but I have since found that it is by no means so rare as it had been supposed. All the Pipefishes display it; the Suckers (Lepidogaster), tiny fishes of low organization, manifest it strongly: in the Little Weaver (Trachinus vipera) I have remarked it very distinctly, and with more than common admiration, on account of the unusual beauty of the eyes in this species, which resemble turquoises set in gold.

The Wrasses (Labridœ) have the power of separate motion, but in a less degree: in the Butterfly Blenny (Blennius ocellaris) and the Gattoruginous Blenny (B. gattorugine) it is more or less distinct, in the former more than the latter. The fishes just mentioned (the Blennies and the Wrasses) have the faculty of moving the two eyes in unison as well as independently, apparently at pleasure.

These are all the species in which I have noticed the phenomenon of separate eye-movement, but I