VEGETABLE PBODUCTIONS FEOM CHINA. 107 



sometimes torulose linear bodies, varying, however, much in out- 

 line ; and dispersed among them are a number of small granules, 

 many of which contain a minute nucleus ; while other larger bodies, 

 exhibiting one or two faint traces of concentric circles, are scat- 

 tered about, exactly like the asci of a truffle, but containing only 

 a very small irregular nucleus. Treated with the same chemical 

 tests as the Eoo-ling, it exhibits precisely the same reaction. 

 There is not the slightest trace of starch or cellulose, and it is 

 evident that the structure is not accordant with that of any 

 Fungus or phsenogamous Tuber. 



As there is some outward resemblance between this production 

 and the tuberiform body which precedes the growth of Pedza 

 tuherosa, I have made a comparative examination of the two, and 

 though there is some resemblance as regards chemical reaction, 

 the structure is totally different. In the Peziza tuber the whole 

 mass consists of large threads with very thick gelatinous walls, 

 and an abundant proteinous endochrome. 



No fungus has ever been found on the American or Chinese 

 tubers, and, unfortunately, Pachyma tuber regium, which gives rise 

 to a species of Lentinus, as figured by E-umphius, is quite un- 

 known. It is probably, however, of the same nature with the 

 Pietra funghaja or Fungus-stone of Italy (a mere mass of earth 

 and mycelium), which produces the edible Polyporus tuberaster 

 even in our own hothouses. 



Unfortunately but little light is thrown upon the real nature of 

 these productions by all the specimens and information we possess. 

 Dr. Macbride asserts that the Tuckahoe originates between the 

 wood and bark of living roots ; that it gradually detaches the 

 bark, while it spreads round the wood and converts it into a sub- 

 stance similar to itself; and that if it comes in contact with the 

 root of another tree, that root is also assimilated with it. Speci- 

 mens, however, are wanting to show this transitional state. 



I have still to -notice briefly the third production sent to me 

 by Prof. Horaninow, of which I forward a portion for your inspec- 

 tion. It is evidently closely allied to the native bread of Australia, 

 but differs in the reddish, not black, cuticle, which does not crack 

 and peel off, the total absence of an intermediate stratum between 

 the cuticle and central mass, and the want of large clavate cells 

 amongst the linear bodies of which the central mass is composed. 

 The internal substance is marbled like a truffle ; but there is not 

 a trace of fruit, and in consequence, together with Mylitta austra- 

 lis, it must be considered of very doubtful affinity. 



