The Glow-Worm and Other Beetles 



Those of an intense black may be likened 

 to dyers' products: they are completely im- 

 pregnated with the colouring matter, which 

 is part and parcel of the molecular constitu- 

 tion and cannot be isolated by the nitric 

 solvent. The others, red, yellow or white, 

 are actually painted: on a translucid sheet is 

 a wash of urinary pigment, which is dis- 

 charged by the minute ducts issuing from the 

 adipose layer. When the action of the ni- 

 tric acid has ceased, the transparent circles 

 of the latter stand out against the black back- 

 ground of the former. 



Yet one more example taken from a dif- 

 ferent order. As regards elegance of cos- 

 tume, the Banded Epeira ^ is the most highly 

 favoured of our Spiders. On the upper sur- 

 face of her corpulent belly alternate. In trans- 

 versal bands, bright black, a vivid yellow like 

 that of yolk of egg and a dazzling white like 

 that of snow. The black and yellow also 

 show underneath, but arranged differently. 

 The yellow. In particular, forms two longi- 

 tudinal ribbons, ending in orange-red on 

 either side of the spinnerets. A pale purple 

 is faintly diffused over the sides. 



Examined from the outside with the lens, 



1 Cf. The Life of the Spider: chaps, ii., vii., xi. and xiii. 

 — Translator's Note. 



284 



