330 THE ZOOLOGIST. 



J. Storej', who describes the limits of insect vision, in the terms 

 of a coarse mosaic or rough imperfect representation of the 

 external world, the result of the perceptions acquired by their 

 compound eyes ; while he asserts that *' the insect cannot see 

 more details upon its own antennae, close as they are to it, than 

 we can with our own naked eye. We must therefore dismiss 

 from our thoughts the mistaken impression that insects see very 

 minute objects far beyond human vision."* Nor can we, as 

 remarked before, conclude that they appreciate colours similarly 

 to ourselves. The question was well put by Lord Rayleigh some 

 years ago, who added the remark : — '* Surely this is a good deal 

 to take for granted when it is known that even among ourselves 

 colour-vision varies greatly, and that no inconsiderable number 

 of persons exist to whom, for example, the red of the scarlet 

 geranium is no bright colour at all, but almost a match with the 

 leaves." f The only rejoinder to this proposition at the time 

 was the suggested argument based on the spectrum of the light 

 of the Firefly, which had been found to be perfectly continuous, 

 without traces of lines either bright or dark, and to extend from 

 about the line C in the scarlet to F in the blue. It is composed 

 of rays which act powerfully on the eye, but produce little 

 thermal or actinic effect. In other words, the fly, in producing 

 its light, wastes but little of its power. The writer, however, 

 was careful to add : — " Tliis, it is true, tells us nothing as to the 

 colour sensations of the insect, but it appears to show that the 

 same rays are luminous to its eyes which are luminous to ours."t 

 This is precisely the view here again suggested — the same ray or 

 object is seen as by ourselves; but the colour, size, or structure 

 of both respectively may be altogether different, or at least con- 

 siderably diverse from those apprehended by our own cognitions. 

 This does not, however, necessarily invalidate the conclusions 

 we have formed as to the actual existence of some forms of pro- 

 tection by what we understand as mimicry or protective resem- 

 blance. It may be taken to prove that both the object resembled 



- ' Sci. Proc. R. Dubl. Soc' n. s. vol. viii. p. 288.— C/. Job. Miiller 

 (' Zur Vergleichenden Physiologie des Gesichtssinnes,' p. 822), and Bur- 

 meister (' Manual Entomology,' Eng. transl. p. 489). 



f ' Nature,' vol. xi. p. 6. 



\ J. J. Murphy, ibid. p. 28. 



