Insects and Mushrooms 



tain soluble, colourless Indigo? One would 

 say so, if certain properties did not give 

 grounds for doubt. When subjected to pro- 

 longed exposure to the air, the boleti that are 

 apt to turn blue, particularly the most remark- 

 able. Boletus cyanescens, lose their colour, in- 

 stead of retaining the deep blue which would 

 be a sign of real indigo. Be this as it may, 

 these mushrooms contain a colouring-prin- 

 ciple which is very liable to change under the 

 influence of the air. Why should we not re- 

 gard it as the cause of the black tint when the 

 maggots have liquefied the boleti which turn 

 blue ? The others, those with the white flesh, 

 the edible boletus, for instance, do not assume 

 this asphalty appearance once they are lique- 

 fied by the grubs. 



All the boleti that change to blue when 

 broken have a bad reputation; the books treat 

 them as dangerous, or at least open to sus- 

 picion. The name of Satanic awarded to one 

 of them is an ample proof of our fears. The 

 caterpillar and the maggot are of another 

 opinion : they greedily devour what we hold in 

 dread. Now here is a strange thing: those 

 passionate devotees of Boletus Satanas abso- 

 lutely refuse certain mushrooms which we find 

 delightful eating, Including the most cele- 

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