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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