462 THE ZOOLOGIST. 



that is because they mistake it for a Hawk, for the longer I 

 observe the more I am convinced that birds and animals often 

 act from causes quite distinct from those which at first sight 

 appears sufficient to account for their motions. 1 '* The dread 

 experienced by small birds for their larger brethren of prey is 

 probably open to qualification, for Gilbert White tells us of a 

 Swallow who " built its nest on the wings and body of an Owl 

 that happened by accident to hang dead and dry from the rafters 

 of a barn."f 



As with " mimicry," so the theory of " warning colours " may 

 be hastily predicated. Among Flatworms in the terricolous 

 Triclads or Land Planarians, some species "are frequently banded 

 or striped with brilliant colours. Geoplana ccerulea, Mos., has a 

 blue ventral surface, and is olive-green or dark Prussian blue 

 above. G. splendens, Dendy, is marked dorsally by three stripes 

 of emerald-green alternating with four dark brown longitudinal 

 bands. The mode of colouration, though somewhat variable, is 

 an important specific character. Its significance, however, is not 

 clearly understood. The colours may be a warning signal, as 

 some Geoplana at least are disagreeable to the taste of man and 

 some birds; but since Land Planarians are largely nocturnal 

 animals, living by day under logs, banana-leaves, and in other 

 moist and dark situations, this explanation is clearly insufficient."! 

 Among the Polychaete Worms the same caution is necessary. 

 " Carnivorous forms like Amphinomids and Syllids present as 

 wide a range of tint as the limnivorous forms, like Cirratulus, 

 Sabella, or Maldanids. Shore-lovers and deep-sea dwellers and 

 surface-swimmers all exhibit equally bright or equally sombre 

 tints ; it is therefore difficult and rash to dogmatise on the ' use ' 

 of these colourings to these animals, or to point to this worm 

 as being protectively, to the other as being warningly, coloured ; 

 for we are too ignorant as to the habits of the worms." § 



As we record instances of what appear only capable of being 

 ascribed to "suggestive but mistaken mimicry," we meet with 

 natural resemblances which seem to fall under a category of 



* ' Wild Life in a Southern County,' p. 265. 



f ' Nat. Hist. Selborne ' (Harting's edit.), p. 194. 



| F. W. Gamble, 'Cambridge Nat. Hist.' vol. ii. p. 33. 



§ W. Blaxland Benham, ibid. p. 293. 



