192 
VEGETABLE STRUCTURE. 
We have feen the VeiTel cleared of all the matter, and we are now to 
examine its ftrudture. This is very fimple ; it is compofed of two Mem- 
branes ; both pellucid; but the outer one the thickefl. Fig. 16. The 
inner Membrane riles into little Blebs, like round Bladders, at fmall dif- 
tances from, one another, and thele are properly the Seed-VcfTels of the 
Truffle, b'ig. 17. Four Seeds are lodged in each, 18 : when we fee a 
fmaller number, it is owing to the Knife cutting the Velfel in two. 
Each Seed is real y a Truffle. We fee them at fird fmall, round, 
and I'mooth, and they appear no more than Pc.rticles of the outer Mem- 
brane of the great Vefl'el, raifed and loofened within the Bleb made by the 
rifing of the inner Skin, Fig. 19: as the Truffle grows toward ripenefs 
they enlarge, grow duilcy, and rough, 20; and in the end, while they are 
yet in the body of the Truffle, they acquire even their brown outer 
Coat ; and they are Truffles ; wanting only growth. 
Thus we fee the courfe of Nature in the formation of the Truffle. 
The outer Membrane of the great Velfel is the elfential part, analogous to 
the Flelhy Subllance in larger Plants. This has its three Coats, the two 
Rinds, and the Flelh anlwering the Blea ; and this inner Membrane in the 
place of Pith, from which, i. deed, there run Fibrils, making a true tho’ 
very light Pith in the Lobes and between the Seeds. 
In all Vegetables the cfl'cntial part, or fubllance, fends off at its extre- 
mity Particles, which being lodged in the Seed, are capable of growth into 
new Plants. In this plain Vegetable, the Truffle, there is nothing of 
the apparatus of Filaments, and the other parts of a Flower. But Parti- 
cles of the efiential part, which is the outer Membrane of the great Vef- 
fel, feparate themfelves, and are defended by a little Bleb of the raifed in- 
ner Membrane. Here they float in a clear liquor, and they immediately 
grow. They are at flrfl: only round pieces of the Membrane itl'eif ; but 
this forms all its own Coats, as the Particle in the Seeds of Plants does ; 
and by cutting Truffles at various periods of ripenefs, we may even fee 
this done. Fnfl; the Flefli, or pure Pulp, is formed, and the little Seed 
then is fomewhat larger, and more opake. After this the yellowifh Rind 
is formed, and it is then more opake, and fomewhat coloured. Fig. 21 : 
and, finally, the outer Bark is alfo formed ; it is then obicure and rough. 
Fig. 22. It is a perfedt Truffle, and requires only to encrease in fize 
to be what its parent was. 
Altho’ the Seeds of the Truffle are thus extreamly numerous, and 
to the Microfeope very plain and diflind:, nothing is more difficult than to 
get them clear of the Velfel, and feparate for examination. The Reafon 
is 
