252 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



and, while they are rare in Sweden, they increase gradually in 

 number as we advance from England to France and Italy, 

 attaining their maximum probably about Turin. A large 

 quantity of truffles, placed in my hands by Professor Fries, from 

 the Ukrain, proved generally identical with the species of 

 Western Europe. The common moulds are altogether ubiqui- 

 tous; Eurotium is as destructive in the southern as the 

 northern hemisphere, and smut and mildew are alike injurious 

 wherever cereals are cultivated. Little is known of tropical 

 moulds. The curious forms figured rather roughly by Martins 

 have been observed by no one else, and at present are involved 

 in some obscurity from want of information as to their inti- 

 mate structiire. 



248. But few undoubted instances of Fungi occur in a fossil 

 state. Dr. Brown, however, has informed me that he has seen 

 mycehum in the cells of fossil wood ; and the amber of the 

 tertiary formation* contains PenicilUwm and another genus 

 in a state of such perfection as to make it almost certain that 

 other Fungi were not wanting in those periods of the world, 

 though in general they may not have been able to resist decom- 

 position. A few doubtful productions are assigned to Fungi 

 in lists of fossil plants, but mere external form without oppor- 

 tunity of examining structure is too fallacious to command much 

 confidence. Polyporus fomentarius is j)reserved admirably 

 in the fens of Cambridgeshire, but not according with British 

 forms of the present day. In the Kew Museum, a specimen 

 may be seen side by side with one from Sikkim, the accord- 

 ance of the two being quite perfect. -f- 



249. In our own country, with the exception of some three 

 or four species, Fungi enter but little into our markets, 

 though the consumption of some of these is very considerable. 

 Agaricus cami)estris and arvensis are the source of the 

 .greater portion of the really wholesome and fine-flavoured 

 katsup ; but thousands of bottles are made every year without 



* Ann. of Nat. Hist., n. s., vol. 2, p. 369, tab. 11, 12. I am not certain 

 that the third genus, referred to Streptothrix, is properly organic, 

 t Journ. of Linu. Soc, vol. 1, jj. 52. 



