230 MR. GEORGE MURRAY ON TWO NEW SPECIES OF LENTINUS. 
I have therefore ventured to restore the margin of the pileus in the accompanying 
figure of it. 
I was next disappointed in failing to identify the sclerotium with Pachyma. The 
tissue is, as the figure shows, that of a true sclerotium, a plexus of hyphze densely 
interwoven, and, while varying in the diameter of the filaments, yet fairly uniform. 
Pachyma on the other hand (see Trans. Linn. Soc. vol. xxiii. tab. ix. figs. 7 and 8) 
appears to consist of masses of pectine traversed by fungal hyphæ, and to deserve the 
name of a sclerotioid body rather than of а sclerotium. The Rev. Mr. Berkeley, in 
referring (Introduction to Cryptogamic Botany, p. 288) to the Tuckahoe or Indian 
Bread of North America (Pachyma Cocos, Fr.), says that “it is not a true fungus, but a 
state of certain unknown roots in which their structure is converted into pectic acid.” 
The Tuckahoe or Indian Bread has been recently reported on by Prof. J. Howard Gore 
at р. 687 of the Annual Report of the Board of Regents of the Smithsonian Institution 
for the year 1881 (Washington, 1883). Prof. Gore made “a critical inspection of its 
structure, and an examination of many specimens at different stages of development; ” 
and as a result of this he found among other things that “аф some season of the year 
spores are given off and transmitted by insects, water, or other natural means, and are 
attached to the roots of other trees suitable for its production." Undoubtedly the 
investigation of so obscure a question as the nature of Pachyma requires a suitable | 
state not only in the development of the material, but in that of the observer as well; and 
judging by the evidence of Prof. Gore's report, I venture to think he has not brought us 
much nearer an explanation of this matter. Mr. Berkeley in a paper on Pachyma from 
China (Linn. Soc. Journ. of Proc. vol. iii. Bot. p. 107) says, ** 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 Rumphius, is quite unknown. It 
is probably, however, of the same nature with the Pietra funghaja or fungus-stone of Italy 
(а mere mass of earth and mycelium)" Whether Fries was right in interpreting 
Rumphius’s Tuber regium to be a Pachyma or Mr. Berkeley in thinking it resembled 
the Pietra funghaja, there is no means of determining absolutely from Rumphius’s 
description or figure, though “а mere mass of earth and mycelium” would hardly be 
likely to possess the properties as a food &с. ascribed by Rumphius to his Tuber regium. | 
In this absence of evidence it would be wholly unwarrantable to set up a claim for the 
true sclerotium collected by Mr. Whitmee to be the Tuber regium of Rumphius, though 
a description of it will show a striking correspondence. Its tissues are traversed in all 
directions by rhizoids of Zentinus varying in diameter, and not only by rhizoids of the 
Lentinus actually growing upon it, but by others, one of which I have carefully traced to 
one of the three or four external pits where doubtless previous individuals had grown 
forth (see fig. 1, а). The explanation inevitably suggested by the course of these strings 
of hyphee is that originally a Lentinus spore or spores had germinated upon the surface 
of the sclerotium, had pushed out rhizoids into the mass, and that the mycelium 
thus attaining the interior had become perennial there, producing from time to time 
orn: of Lentinus from the surface under favourable circumstances, such as those 
described by Rumphius for his Tuber regium. Though it is impossible to reach 
