86 INTRODUCTION TO THE STUDY OF FUNGI 



converted to blue on exposure to air, and possibly the colouring 

 matter was indigogen in Boleti. He obtained this pigment, 

 and found that it rapidly passes from yellow to blue, and from 

 blue to brown. While in the blue state it can be again reduced 

 to yellow ; but when it has once become brown it seems to be 

 destroyed, as the blue colour could not by any means be 

 restored. The blue matter contains neither indigo nor aniline. 

 From this it will be seen that he was not successful in deter- 

 mining this colouring matter in Boletus. It is not by any 

 means certain that this colouring matter, whatever it may be, 

 has any relation to the toxicological properties of the Fungus, 

 as has been generally supposed, although its development is 

 strong in poisonous species. 



Very little can be said of the nature of the odours which 

 pertain to Fungi, but Stewart has made some suggestions in this 

 direction. He says that the volatile alkaloid called tri-methyl- 

 amine is a colourless liquid with a powerful fishy odour, and 

 is, in fact, the cause of the smell of decayed fish ; it is found also 

 in the flowers of the hawthorn, and in some Fungi, as in ergot 

 of rye and putrefying yeast. He also hints at the possibility 

 of the odour of Phallus impudicus and that of Clathrus cancel- 

 latus being derived from the same source. There are some 

 Agarics which possess the odour of putrid fish, but they are 

 small and not common, hence the source of odour is unknown. 



The toxicological ingredients of Fungi have been investigated 

 several times, but the results have hardly accorded in any two 

 cases, and are still open to inquiry. Bohm has especially 

 studied Boletus luridus, and found large quantities of choline, 

 together with a substance similar to cholesterin, small 

 quantities of muscarine, and luridic acid, which crystallises in 

 brilliant red needles, and yields succinic acid on distillation. 

 Essentially the same substances were found in Amanita 

 pantherina, but in that the acid crystallises in yellow crusts. 1 

 The Fly Agaric {Amanita muscaria) yields two alkaloids — 

 muscarine and amanitine. Muscarine is a strong narcotic, 

 and in some respects antagonistic to atropin. Amanitine is 

 identical with the animal bases choline, mentioned above in 

 Boletus luridus, and with neurine. An eminent physician and 

 1 Journ. Chem. Soc, 1885, p. 1008. 



