3 o COLIN CLOUT'S CALENDAR. 



coloured exactly like it, and so closely imitate it in many 

 ways that I have often narrowly examined a piece of the 

 weed freshly brought up in a bucket, and yet failed to 

 detect any sign of life till I lifted the spray from the 

 water and so compelled the hide-aways to reveal them- 

 selves. There is one pipe-fish, indeed, from the Austra- 

 lian coasts, which so exactly mimics the fucus in which it 

 lurks that nobody would believe it is a fish rather than 

 a branch of the weed round which it curls, until he has 

 dissected it. The necessity for such close resemblances 

 is the best possible proof of acute sight in fishes exactly 

 analogous to our own. 



That this faculty of vision includes a perception of 

 colour as well as form is shown by the same facts ; but 

 there are other facts which seem to indicate it yet more 

 clearly. The teleosteans, which possess these developed 

 eyes and optic centres, are the only fish in which Mr. 

 Darwin has noted the occurrence of ornamental colours 

 or appendages, due, as he believes, to selective pre- 

 ferences on the part of the animals themselves. It is 

 curious, too, that all the indirect proofs of colour-sense 

 in fishes occur among this same group. -The ornamental 

 colours generally coexist with very excitable tempers, as 

 is also the case with such higher animals as the mandrill, 

 the peacock, and the humming-birds ; and in the little 

 fighting-fish kept as pets by the Siamese, the brilliant 

 hues are only displayed on the appearance of a rival or 

 of the fish's own reflection in a mirror. The moment 

 the little creature sees another of his own kind, he ex- 

 hibits all his colouring, and rushes against his enemy 

 covered with metallic tints, and waving his projected 

 gills like the wattles of a turkey-cock. Almost all the 



